diff --git a/crypto/sm2/build.info b/crypto/sm2/build.info
index 6b650d73..8dcca88e 100644
--- a/crypto/sm2/build.info
+++ b/crypto/sm2/build.info
@@ -1,3 +1,3 @@
 LIBS=../../libcrypto
 SOURCE[../../libcrypto]=sm2_err.c sm2_asn1.c sm2_id.c sm2_sign.c sm2_enc.c \
-			sm2_oct.c sm2_exch.c sm2_kmeth.c
+			sm2_oct.c sm2_exch.c sm2_kmeth.c sm2_cosign.c
diff --git a/crypto/sphincs/.clang-format b/crypto/sphincs/.clang-format
new file mode 100644
index 00000000..95ba58ea
--- /dev/null
+++ b/crypto/sphincs/.clang-format
@@ -0,0 +1,46 @@
+AccessModifierOffset: 0
+AlignEscapedNewlinesLeft: false
+AlignTrailingComments: true
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortFunctionsOnASingleLine: true
+AllowShortIfStatementsOnASingleLine: true
+AllowShortLoopsOnASingleLine: true
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: false
+BinPackParameters: false
+BreakBeforeBinaryOperators: false
+BreakBeforeBraces: Attach
+BreakBeforeTernaryOperators: false
+BreakConstructorInitializersBeforeComma: false
+ColumnLimit: 80
+CommentPragmas: ''
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 0
+ContinuationIndentWidth: 0
+Cpp11BracedListStyle: false
+DerivePointerBinding: false
+IndentCaseLabels: false
+IndentFunctionDeclarationAfterType: false
+IndentWidth: 4
+Language: Cpp
+MaxEmptyLinesToKeep: 2
+NamespaceIndentation: None
+ObjCSpaceAfterProperty: true
+ObjCSpaceBeforeProtocolList: true
+PenaltyBreakBeforeFirstCallParameter: 100
+PenaltyBreakComment: 100
+PenaltyBreakFirstLessLess: 0
+PenaltyBreakString: 100
+PenaltyExcessCharacter: 1
+PenaltyReturnTypeOnItsOwnLine: 20
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeParens: Always
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles: false
+SpacesInCStyleCastParentheses: false
+SpacesInContainerLiterals: false
+SpacesInParentheses: false
+Standard: Cpp11
+TabWidth: 4
+UseTab: Never
diff --git a/crypto/sphincs/.gitignore b/crypto/sphincs/.gitignore
new file mode 100644
index 00000000..3a09df25
--- /dev/null
+++ b/crypto/sphincs/.gitignore
@@ -0,0 +1,3 @@
+bench
+*.o
+*.dSYM
diff --git a/crypto/sphincs/LICENSE b/crypto/sphincs/LICENSE
new file mode 100644
index 00000000..6ed4a65b
--- /dev/null
+++ b/crypto/sphincs/LICENSE
@@ -0,0 +1,13 @@
+Copyright 2017 Nagravision S.A.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
\ No newline at end of file
diff --git a/crypto/sphincs/Makefile b/crypto/sphincs/Makefile
new file mode 100644
index 00000000..5f6d6e6a
--- /dev/null
+++ b/crypto/sphincs/Makefile
@@ -0,0 +1,52 @@
+SRC=$(wildcard *.c) $(wildcard primitives/*.c)
+OBJ=$(patsubst %.c, %.o, $(SRC))
+
+CFLAGS_COMMON=-std=c89 -pedantic -Wall -Wextra -Wno-long-long -march=native
+LDFLAGS=-lcrypto
+
+VERSION_S= -DPORS_k=24 -DMERKLE_h=5  -DGRAVITY_d=1  -DGRAVITY_c=10
+VERSION_M= -DPORS_k=32 -DMERKLE_h=5  -DGRAVITY_d=7  -DGRAVITY_c=15
+VERSION_L= -DPORS_k=28 -DMERKLE_h=5  -DGRAVITY_d=10 -DGRAVITY_c=14
+
+VERSION=$(VERSION_S)
+
+CFLAGS_COMMON+=$(VERSION)
+CFLAGS=$(CFLAGS_COMMON) -O3 -fomit-frame-pointer
+CFLAGS_SANITIZED=$(CFLAGS_COMMON) -fsanitize=address,undefined -g
+
+KERNEL_NAME := $(shell uname -s)
+ifeq ($(KERNEL_NAME), Darwin)
+	CFLAGS += -I/usr/local/opt/openssl/include
+	LDFLAGS += -L/usr/local/opt/openssl/lib
+endif
+
+all: help
+
+help:
+			@echo "Please choose a target:"
+			@echo "\tanalyze\t\t runs static analyzers"
+			@echo "\tbench\t\t runs speed benchmarks"
+			@echo "\tclean\t\t cleans up"
+			@echo "\tformat\t\t formats the code using .clang-format rules"
+
+bench:		$(SRC)
+			$(CC) $(CFLAGS) $(LDFLAGS) $^ -o bench
+			./bench
+
+format:
+			clang-format -i *.c *.h
+
+analyze:
+			cppcheck . --std=c89
+			scan-build gcc -c $(CFLAGS_SANITIZED) *.c
+			cppclean .
+			rm -f *.o
+
+cloc:
+			cloc $(wildcard *.c) $(wildcard *.h)
+
+clean:
+			rm -f bench *.dSYM *.o
+
+.PHONY: clean format analyze cloc bench
+
diff --git a/crypto/sphincs/aes.h b/crypto/sphincs/aes.h
new file mode 100644
index 00000000..8a7b25b4
--- /dev/null
+++ b/crypto/sphincs/aes.h
@@ -0,0 +1,10 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#pragma once
+
+#include <stdint.h>
+
+int aesctr256 (uint8_t *out, const uint8_t *sk, const void *counter, int bytes);
+
+int aesctr256_zeroiv (uint8_t *out, const uint8_t *sk, int bytes);
diff --git a/crypto/sphincs/api.h b/crypto/sphincs/api.h
new file mode 100644
index 00000000..a2a66644
--- /dev/null
+++ b/crypto/sphincs/api.h
@@ -0,0 +1,41 @@
+#pragma once
+
+#ifndef CRYPTO_BYTES
+
+/* setting CRYPTO_BYTES to the static structure size, for simplicity,
+   as opposed to the actual message-dependent signature size */
+
+#define CRYPTO_ALGNAME "Gravity-SPHINCS S"
+#define CRYPTO_SECRETKEYBYTES 65568
+#define CRYPTO_PUBLICKEYBYTES 32
+#define CRYPTO_BYTES 15728 // 12640
+
+#if 0
+#define CRYPTO_ALGNAME "Gravity-SPHINCS M"
+#define CRYPTO_SECRETKEYBYTES 2097184
+#define CRYPTO_PUBLICKEYBYTES 32
+#define CRYPTO_BYTES 34064 // 28929
+#endif
+
+#if 0
+#define CRYPTO_ALGNAME "Gravity-SPHINCS L"
+#define CRYPTO_SECRETKEYBYTES 1048608
+#define CRYPTO_PUBLICKEYBYTES 32
+#define CRYPTO_BYTES 38768 // 35168
+#endif
+
+#endif
+
+int crypto_sign_keypair (unsigned char *pk, unsigned char *sk);
+
+int crypto_sign (unsigned char *sm,
+                 unsigned long long *smlen,
+                 const unsigned char *m,
+                 unsigned long long mlen,
+                 const unsigned char *sk);
+
+int crypto_sign_open (unsigned char *m,
+                      unsigned long long *mlen,
+                      const unsigned char *sm,
+                      unsigned long long smlen,
+                      const unsigned char *pk);
diff --git a/crypto/sphincs/batch.c b/crypto/sphincs/batch.c
new file mode 100644
index 00000000..3159b591
--- /dev/null
+++ b/crypto/sphincs/batch.c
@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#include "batch.h"
+
+#include "merkle.h"
+
+int batch_init (struct batch_buf *buf) {
+    buf->count = 0;
+    return GRAVITY_OK;
+}
+
+int batch_append (struct batch_buf *buf, const uint8_t *msg, uint64_t len, uint32_t *index) {
+    if (buf->count == MAX_BATCH_COUNT) return GRAVITY_ERR_BATCH;
+
+    /* TODO: randomize this hash? */
+    hash_to_N (&buf->buf[buf->count], msg, len);
+
+    *index = buf->count;
+    ++buf->count;
+
+    return GRAVITY_OK;
+}
+
+int batch_group (struct batch_group *group, struct batch_buf *buf) {
+    int height = LOG_MAX_BATCH_COUNT;
+    int n = 1 << height;
+    int offset = n - 1;
+
+    struct hash *src;
+    struct hash *dst;
+    uint32_t count;
+    int i;
+
+    /* Check batch count */
+    count = buf->count;
+    if (count == 0) return GRAVITY_ERR_BATCH;
+    group->count = count;
+
+    /* Leaves */
+    dst = &group->tree[offset];
+
+    hashcpyN (dst, buf->buf, count);
+    for (i = count; i < n; ++i) hashcpy (&dst[i], &buf->buf[0]);
+
+    /* Compress until root */
+    while (height > 0) {
+        offset >>= 1;
+        --height;
+
+        src = dst;
+        dst = &group->tree[offset];
+        hash_compress_pairs (dst, src, 1 << height);
+    }
+
+    return GRAVITY_OK;
+}
+
+int batch_extract (const struct batch_group *group, struct batch_auth *auth, uint32_t index) {
+    int height = LOG_MAX_BATCH_COUNT;
+    int n = 1 << height;
+    int offset = n - 1;
+
+    uint32_t count;
+    int i, sibling;
+
+    /* Check batch count */
+    count = group->count;
+    if (index >= count) return GRAVITY_ERR_BATCH;
+
+    /* Convert row index into tree index */
+    auth->index = offset + index;
+
+    /* Copy auth path */
+    for (i = 0; i < height; ++i) {
+        sibling = index ^ 1;
+        hashcpy (&auth->auth[i], &group->tree[offset + sibling]);
+        index >>= 1;
+        offset >>= 1;
+    }
+
+    return GRAVITY_OK;
+}
+
+void batch_compress_auth (struct hash *node,
+                          const struct batch_auth *auth,
+                          const uint8_t *msg,
+                          uint64_t len) {
+    /* Compute Merkle tree root */
+    int height = LOG_MAX_BATCH_COUNT;
+    hash_to_N (node, msg, len);
+    merkle_compress_auth (node, auth->index, auth->auth, height);
+}
diff --git a/crypto/sphincs/batch.h b/crypto/sphincs/batch.h
new file mode 100644
index 00000000..e2f65edf
--- /dev/null
+++ b/crypto/sphincs/batch.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#pragma once
+
+#include "hash.h"
+
+struct batch_buf {
+    struct hash buf[MAX_BATCH_COUNT];
+    uint32_t count;
+};
+
+struct batch_group {
+    struct hash tree[2 * MAX_BATCH_COUNT - 1];
+    uint32_t count;
+};
+
+struct batch_auth {
+    struct hash auth[LOG_MAX_BATCH_COUNT];
+    uint32_t index;
+};
+
+int batch_init (struct batch_buf *buf);
+
+int batch_append (struct batch_buf *buf, const uint8_t *msg, uint64_t len, uint32_t *index);
+
+int batch_group (struct batch_group *group, struct batch_buf *buf);
+
+int batch_extract (const struct batch_group *group, struct batch_auth *auth, uint32_t index);
+
+void batch_compress_auth (struct hash *node,
+                          const struct batch_auth *auth,
+                          const uint8_t *msg,
+                          uint64_t len);
diff --git a/crypto/sphincs/bench.c b/crypto/sphincs/bench.c
new file mode 100644
index 00000000..a14dc477
--- /dev/null
+++ b/crypto/sphincs/bench.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+
+#include "gravity.h"
+#include "randombytes.h"
+#include "sign.h"
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/time.h>
+
+#define SKLEN sizeof (struct gravity_sk)
+#define PKLEN sizeof (struct gravity_pk)
+#define SIGLEN sizeof (struct gravity_sign)
+#define N 32
+#define ROUNDS 3
+
+
+int main () {
+
+    unsigned long long smlen;
+    unsigned long long mlen = N;
+    uint8_t sk[SKLEN];
+    uint8_t pk[PKLEN];
+    uint8_t m[N];
+    uint8_t *sm = malloc (N + SIGLEN);
+    struct timeval tm1, tm2;
+    unsigned long long usecs;
+    int ret = -1;
+    int i;
+
+    if (!sm) {
+        fprintf (stderr, "error: sm malloc failed\n");
+        ret = 1;
+        goto label_exit_0;
+    }
+
+    printf ("k\t%d\n", PORS_k);
+    printf ("h\t%d\n", MERKLE_h);
+    printf ("d\t%d\n", GRAVITY_d);
+    printf ("c\t%d\n", GRAVITY_c);
+    printf ("sk len\t%d\n", (int)SKLEN);
+    printf ("pk len\t%d\n", (int)PKLEN);
+    printf ("sig len\t%d\n", (int)SIGLEN);
+
+#define MEASURE(s)                                                                 \
+    do {                                                                           \
+        gettimeofday (&tm2, NULL);                                                 \
+        usecs = 1000000 * (tm2.tv_sec - tm1.tv_sec) + (tm2.tv_usec - tm1.tv_usec); \
+        printf ("\n# %s\n", s);                                                    \
+        printf ("%.2f usec\n", (double)usecs);                                     \
+    } while (0)
+
+    randombytes (m, N);
+
+    gettimeofday (&tm1, NULL);
+
+    if (crypto_sign_keypair (pk, sk)) {
+        fprintf (stderr, "error: crypto_sign_keypair failed\n");
+        ret = 1;
+        goto label_exit_2;
+    }
+
+    MEASURE ("crypto_sign_keypair");
+
+    for (i = 0; i < ROUNDS; ++i) {
+
+        gettimeofday (&tm1, NULL);
+
+        if (crypto_sign (sm, &smlen, m, mlen, sk)) {
+            fprintf (stderr, "error: crypto_sign failed\n");
+            ret = 1;
+            goto label_exit_2;
+        }
+
+        MEASURE ("crypto_sign");
+        gettimeofday (&tm1, NULL);
+
+
+        if (crypto_sign_open (m, &mlen, sm, smlen, pk)) {
+            fprintf (stderr, "error: crypto_sign_open failed\n");
+            ret = 1;
+            goto label_exit_2;
+        }
+
+        m[0] ^= sm[33];
+
+        MEASURE ("crypto_sign_open");
+    }
+
+    ret = 0;
+label_exit_2:
+    free (sm);
+label_exit_0:
+    return ret;
+}
diff --git a/crypto/sphincs/common.h b/crypto/sphincs/common.h
new file mode 100644
index 00000000..1318b9f1
--- /dev/null
+++ b/crypto/sphincs/common.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#pragma once
+
+#define HASH_SIZE 32
+
+#define WOTS_LOG_ell1 6
+#define WOTS_ell1 (1 << (WOTS_LOG_ell1))
+#define WOTS_chksum 3
+#define WOTS_ell ((WOTS_ell1) + (WOTS_chksum))
+#define WOTS_w 16
+
+/* set by compile flags */
+#if 0
+#define PORS_k 28
+#define MERKLE_h 5
+#define GRAVITY_d 10
+#define GRAVITY_c 14
+#endif
+
+#define PORS_tau 16
+#define PORS_t (1 << (PORS_tau))
+
+#define MERKLE_hhh (1 << (MERKLE_h))
+
+#define GRAVITY_ccc (1 << (GRAVITY_c))
+#define GRAVITY_h ((MERKLE_h) * (GRAVITY_d) + (GRAVITY_c))
+
+#if GRAVITY_h < 64
+#define GRAVITY_mask ~(0xFFFFFFFFFFFFFFFFull << (GRAVITY_h))
+#else
+#define GRAVITY_mask 0xFFFFFFFFFFFFFFFFull
+#endif
+
+#define LOG_MAX_BATCH_COUNT 10
+#define MAX_BATCH_COUNT (1 << (LOG_MAX_BATCH_COUNT))
+
+
+#define GRAVITY_OK 0
+#define GRAVITY_ERR_VERIF 1
+#define GRAVITY_ERR_ALLOC 2
+#define GRAVITY_ERR_BATCH 3
+
+#define U8TO32(p)                                                              \
+    (((uint32_t) ((p)[0]) << 24) | ((uint32_t) ((p)[1]) << 16) |               \
+     ((uint32_t) ((p)[2]) << 8) | ((uint32_t) ((p)[3])))
diff --git a/crypto/sphincs/gravity.c b/crypto/sphincs/gravity.c
new file mode 100644
index 00000000..6e8baa94
--- /dev/null
+++ b/crypto/sphincs/gravity.c
@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+
+#include "gravity.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+
+int gravity_gensk (struct gravity_sk *sk) {
+    int n = GRAVITY_ccc;
+    struct hash *src;
+    struct hash *dst = sk->cache;
+    struct merkle_pk mpk;
+    struct address address;
+    int i;
+    int res;
+
+    /* Create sub Merkle trees */
+    address.layer = 0;
+    for (i = 0; i < n; ++i) {
+        address.index = i * MERKLE_hhh;
+        res = merkle_genpk (&sk->seed, &address, &mpk);
+        if (res != GRAVITY_OK) return res;
+
+        hashcpy (&dst[i], &mpk.k);
+    }
+
+    /* Cache layers of Merkle tree */
+    for (i = 0; i < GRAVITY_c; ++i) {
+        src = dst;
+        dst += n;
+        n >>= 1;
+
+        hash_compress_pairs (dst, src, n);
+    }
+
+    return GRAVITY_OK;
+}
+
+int gravity_genpk (const struct gravity_sk *sk, struct gravity_pk *pk) {
+    hashcpy (&pk->k, &sk->cache[2 * GRAVITY_ccc - 2]);
+
+    return GRAVITY_OK;
+}
+
+int gravity_sign (const struct gravity_sk *sk, struct gravity_sign *sign, const struct hash *msg) {
+    struct hash buf[2];
+    struct address address;
+    struct pors_subset subset;
+    struct pors_sk *psk;
+    struct porst_pk ppk;
+    struct merkle_pk mpk;
+    struct hash h;
+    int layer;
+    int res;
+#if GRAVITY_c > 0
+    int offset;
+    int n = GRAVITY_ccc;
+    int i, sibling;
+#endif
+
+    /* Generate "randomness" from message and secret salt */
+    hashcpy (&buf[0], &sk->salt);
+    hashcpy (&buf[1], msg);
+    hash_2N_to_N (&sign->rand, buf);
+
+    /* Generate address and PORST indices */
+    pors_randsubset (&sign->rand, msg, &address.index, &subset);
+
+    /* PORST */
+    psk = malloc (sizeof (struct pors_sk));
+    if (psk == NULL) return GRAVITY_ERR_ALLOC;
+
+    address.layer = GRAVITY_d;
+    pors_gensk (&sk->seed, &address, psk);
+
+    res = octoporst_sign (psk, &sign->op_sign, &ppk, &subset);
+    /* TODO: wipe key */
+    free (psk);
+
+    if (res != GRAVITY_OK) return res;
+
+    /* Store PORST pubkey into h */
+    hashcpy (&h, &ppk.k);
+
+    /* Hyper tree */
+    for (layer = 0; layer < GRAVITY_d; ++layer) {
+        /* Sign h with Merkle tree and obtain public key */
+        --address.layer;
+        res = merkle_sign (&sk->seed, &address, &sign->merkle[layer], &h, &mpk);
+        if (res != GRAVITY_OK) return res;
+        hashcpy (&h, &mpk.k);
+
+        /* Reduce address for next layer */
+        address.index >>= MERKLE_h;
+    }
+
+#if GRAVITY_c > 0
+    /* Cached Merkle tree */
+    offset = 0;
+    for (i = 0; i < GRAVITY_c; ++i) {
+        sibling = address.index ^ 1;
+        hashcpy (&sign->auth[i], &sk->cache[offset + sibling]);
+
+        address.index >>= 1;
+        offset += n;
+        n >>= 1;
+    }
+#endif
+
+    return GRAVITY_OK;
+}
+
+int gravity_verify (const struct gravity_pk *pk,
+                    const struct gravity_sign *sign,
+                    const struct hash *msg) {
+    struct address address;
+    struct pors_subset subset;
+    struct porst_pk ppk;
+    struct merkle_pk mpk;
+    struct hash h;
+    int layer;
+    int res;
+
+    /* Generate address and PORST indices */
+    pors_randsubset (&sign->rand, msg, &address.index, &subset);
+
+    /* PORST */
+    res = octoporst_extract (&ppk, &sign->op_sign, &subset);
+    if (res != GRAVITY_OK) return res;
+
+    /* Store PORST pubkey into h */
+    hashcpy (&h, &ppk.k);
+
+    /* Hyper tree */
+    address.layer = GRAVITY_d;
+    for (layer = 0; layer < GRAVITY_d; ++layer) {
+        /* Obtain Merkle tree root */
+        --address.layer;
+        merkle_extract (&mpk, &address, &sign->merkle[layer], &h);
+        hashcpy (&h, &mpk.k);
+
+        /* Reduce address for next layer */
+        address.index >>= MERKLE_h;
+    }
+
+#if GRAVITY_c > 0
+    /* Cached Merkle tree */
+    merkle_compress_auth (&h, address.index, sign->auth, GRAVITY_c);
+#endif
+
+    if (hashcmp (&h, &pk->k)) return GRAVITY_ERR_VERIF;
+
+    return GRAVITY_OK;
+}
+
+int gravity_loadsign (struct gravity_sign *sign, const uint8_t *_sign, size_t _len) {
+    size_t baselen = HASH_SIZE + GRAVITY_d * sizeof (struct merkle_sign)
+#if GRAVITY_c > 0
+                     + GRAVITY_c * HASH_SIZE
+#endif
+    ;
+
+    if (_len < baselen) return GRAVITY_ERR_VERIF;
+    _len -= baselen;
+
+    memcpy (&sign->rand, _sign, HASH_SIZE);
+    _sign += HASH_SIZE;
+
+    if (octoporst_loadsign (&sign->op_sign, _sign, _len) != GRAVITY_OK)
+        return GRAVITY_ERR_VERIF;
+    _sign += _len;
+
+    memcpy (sign->merkle, _sign, GRAVITY_d * sizeof (struct merkle_sign));
+
+#if GRAVITY_c > 0
+    _sign += GRAVITY_d * sizeof (struct merkle_sign);
+    memcpy (sign->auth, _sign, GRAVITY_c * HASH_SIZE);
+#endif
+
+    return GRAVITY_OK;
+}
+
+int gravity_signcmp (const struct gravity_sign *sign1, const struct gravity_sign *sign2) {
+    if (hashcmp (&sign1->rand, &sign2->rand)) return 1;
+    if (octoporst_signcmp (&sign1->op_sign, &sign2->op_sign)) return 1;
+    if (memcmp (&sign1->merkle, &sign2->merkle, GRAVITY_d * sizeof (struct merkle_sign)))
+        return 1;
+#if GRAVITY_c > 0
+    if (hashcmpN (sign1->auth, sign2->auth, GRAVITY_c)) return 1;
+#endif
+
+    return 0;
+}
diff --git a/crypto/sphincs/gravity.h b/crypto/sphincs/gravity.h
new file mode 100644
index 00000000..fc94320a
--- /dev/null
+++ b/crypto/sphincs/gravity.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#pragma once
+
+#include "merkle.h"
+#include "pors.h"
+
+struct gravity_sk {
+    struct hash seed;
+    struct hash salt;
+    struct hash cache[2 * GRAVITY_ccc - 1];
+};
+
+struct gravity_pk {
+    struct hash k;
+};
+
+struct gravity_sign {
+    struct hash rand;
+    struct octoporst_sign op_sign;
+    struct merkle_sign merkle[GRAVITY_d];
+#if GRAVITY_c > 0
+    struct hash auth[GRAVITY_c];
+#endif
+};
+
+int gravity_gensk (struct gravity_sk *sk);
+
+int gravity_genpk (const struct gravity_sk *sk, struct gravity_pk *pk);
+
+int gravity_sign (const struct gravity_sk *sk, struct gravity_sign *sign, const struct hash *msg);
+
+int gravity_verify (const struct gravity_pk *pk,
+                    const struct gravity_sign *sign,
+                    const struct hash *msg);
+
+/* Serialization */
+int gravity_loadsign (struct gravity_sign *sign, const uint8_t *_sign, size_t _len);
+
+int gravity_signcmp (const struct gravity_sign *sign1, const struct gravity_sign *sign2);
diff --git a/crypto/sphincs/hash.h b/crypto/sphincs/hash.h
new file mode 100644
index 00000000..f3065a29
--- /dev/null
+++ b/crypto/sphincs/hash.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#pragma once
+
+#include "common.h"
+
+#include <stdint.h>
+#include <string.h>
+
+/* TODO: portable alignment */
+struct hash {
+    uint8_t h[HASH_SIZE];
+} __attribute__ ((aligned (16)));
+
+struct address {
+    uint64_t index;
+    uint32_t layer;
+};
+
+
+void hash_N_to_N (struct hash *dst, const struct hash *src);
+void hash_N_to_N_chain (struct hash *dst, const struct hash *src, int chainlen);
+void hash_2N_to_N (struct hash *dst, const struct hash *src);
+void hash_to_N (struct hash *dst, const uint8_t *src, uint64_t srclen);
+
+/* Compress 2*count input hashes into count output hashes, pairwise */
+void hash_compress_pairs (struct hash *dst, const struct hash *src, int count);
+/* Compress count hashes into a single hash */
+void hash_compress_all (struct hash *dst, const struct hash *src, int count);
+/* Compute count hashes in parallel */
+void hash_parallel (struct hash *dst, const struct hash *src, int count);
+/* Compute count hash chains of length chainlen in parallel */
+void hash_parallel_chains (struct hash *dst, const struct hash *src, int count, int chainlen);
+
+
+/* int hashcmp(const struct hash *a, const struct hash *b); */
+#define hashcmp(a, b) memcmp ((a)->h, (b)->h, HASH_SIZE)
+/* int hashcmpN(const struct hash *a, const struct hash *b, size_t count); */
+#define hashcmpN(a, b, N) memcmp ((a)->h, (b)->h, (N)*HASH_SIZE)
+/* void hashcpy(struct hash *dst, const struct hash *src); */
+#define hashcpy(a, b) memcpy ((a)->h, (b)->h, HASH_SIZE)
+/* void hashcpyN(struct hash *dst, const struct hash *src, size_t count); */
+#define hashcpyN(a, b, N) memcpy ((a)->h, (b)->h, (N)*HASH_SIZE)
+/* void hashzero(struct hash *dst); */
+#define hashzero(a) memset ((a)->h, 0, HASH_SIZE)
+/* void swap(struct hash *a, struct hash *b, struct hash *tmp); */
+#define hashswap(a, b, tmp)                                                    \
+    do {                                                                       \
+        (tmp) = (a);                                                           \
+        (a) = (b);                                                             \
+        (b) = (tmp);                                                           \
+    } while (0);
diff --git a/crypto/sphincs/ltree.c b/crypto/sphincs/ltree.c
new file mode 100644
index 00000000..6fe40cf4
--- /dev/null
+++ b/crypto/sphincs/ltree.c
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#include "ltree.h"
+
+void ltree (struct hash *buf, int count, struct hash *root) {
+    struct hash *src = &buf[count];
+    struct hash *dst = &buf[0];
+    struct hash *tmp;
+    int newcount;
+
+    while (count > 1) {
+        /* Swap buffers */
+        hashswap (src, dst, tmp);
+
+        /* Compute all hashes at current layer */
+        newcount = count >> 1;
+        hash_compress_pairs (dst, src, newcount);
+        if (count & 1) {
+            hashcpy (&dst[newcount], &src[count - 1]);
+            ++newcount;
+        }
+
+        count = newcount;
+    }
+
+    hashcpy (root, dst);
+}
diff --git a/crypto/sphincs/ltree.h b/crypto/sphincs/ltree.h
new file mode 100644
index 00000000..6daad929
--- /dev/null
+++ b/crypto/sphincs/ltree.h
@@ -0,0 +1,8 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#pragma once
+
+#include "hash.h"
+
+void ltree (struct hash *buf, int count, struct hash *root);
diff --git a/crypto/sphincs/merkle.c b/crypto/sphincs/merkle.c
new file mode 100644
index 00000000..d9814bc4
--- /dev/null
+++ b/crypto/sphincs/merkle.c
@@ -0,0 +1,266 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#include "merkle.h"
+
+#include <stdlib.h>
+
+int merkle_base_address (const struct address *address, struct address *base_address) {
+    int index = address->index & (MERKLE_hhh - 1);
+    if (base_address != NULL) {
+        base_address->layer = address->layer;
+        base_address->index = address->index - index;
+    }
+    return index;
+}
+
+int merkle_genpk (const struct hash *key, const struct address *address, struct merkle_pk *pk) {
+    struct address base_address;
+    struct hash *buf;
+    struct wots_sk wsk;
+    struct lwots_pk wpk;
+    int j;
+
+    merkle_base_address (address, &base_address);
+
+    buf = merkle_alloc_buf (MERKLE_h);
+    if (buf == NULL) return GRAVITY_ERR_ALLOC;
+
+    /* Leaves */
+    for (j = 0; j < MERKLE_hhh; ++j) {
+        wots_gensk (key, &base_address, &wsk);
+        lwots_genpk (&wsk, &wpk);
+        hashcpy (&buf[j], &wpk.k);
+
+        ++base_address.index;
+    }
+
+    /* Merkle tree */
+    merkle_compress_all (buf, MERKLE_h, &pk->k);
+
+    merkle_free_buf (buf);
+    return GRAVITY_OK;
+}
+
+int merkle_sign (const struct hash *key,
+                 const struct address *address,
+                 struct merkle_sign *sign,
+                 const struct hash *msg,
+                 struct merkle_pk *pk) {
+    struct address base_address;
+    struct hash *buf;
+    struct wots_sk wsk;
+    struct lwots_pk wpk;
+    int index;
+    int j;
+
+    index = merkle_base_address (address, &base_address);
+
+    buf = merkle_alloc_buf (MERKLE_h);
+    if (buf == NULL) return GRAVITY_ERR_ALLOC;
+
+    /* Leaves */
+    for (j = 0; j < MERKLE_hhh; ++j) {
+        wots_gensk (key, &base_address, &wsk);
+        lwots_genpk (&wsk, &wpk);
+        hashcpy (&buf[j], &wpk.k);
+
+        ++base_address.index;
+
+        /* WOTS */
+        if (j == index) wots_sign (&wsk, &sign->wots, msg);
+    }
+
+    /* Merkle tree */
+    merkle_gen_auth (buf, MERKLE_h, sign->auth, index, pk == NULL ? NULL : &pk->k);
+
+    merkle_free_buf (buf);
+    return GRAVITY_OK;
+}
+
+void merkle_extract (struct merkle_pk *pk,
+                     const struct address *address,
+                     const struct merkle_sign *sign,
+                     const struct hash *msg) {
+    struct lwots_pk wpk;
+    int index = merkle_base_address (address, NULL);
+
+    /* WOTS */
+    lwots_extract (&wpk, &sign->wots, msg);
+
+    /* Auth path */
+    merkle_compress_auth (&wpk.k, index, sign->auth, MERKLE_h);
+    hashcpy (&pk->k, &wpk.k);
+}
+
+
+/* Helper functions */
+/* Alloc/free a buffer large enough to store leaves and compress them */
+struct hash *merkle_alloc_buf (int height) {
+    int n = 1 << height;
+    return malloc (2 * n * HASH_SIZE);
+}
+
+void merkle_free_buf (struct hash *buf) {
+    /* TODO: wipe buffer? */
+    free (buf);
+}
+
+/* Compress leaves from level height until root */
+void merkle_compress_all (struct hash *buf, int height, struct hash *root) {
+    int n = 1 << height;
+    struct hash *src = &buf[n];
+    struct hash *dst = &buf[0];
+    struct hash *tmp;
+    int l;
+
+    for (l = 0; l < height; ++l) {
+        /* Swap buffers */
+        hashswap (src, dst, tmp);
+        n >>= 1;
+
+        /* Compute all hashes at current layer */
+        hash_compress_pairs (dst, src, n);
+    }
+
+    hashcpy (root, dst);
+}
+
+/* Compute authentication path */
+void merkle_gen_auth (struct hash *buf, int height, struct hash *auth, int index, struct hash *root) {
+    int n = 1 << height;
+    struct hash *src = &buf[n];
+    struct hash *dst = &buf[0];
+    struct hash *tmp;
+    int l, sibling;
+
+    for (l = 0; l < height; ++l) {
+        /* Copy auth path */
+        sibling = index ^ 1;
+        hashcpy (&auth[l], &dst[sibling]);
+        index >>= 1;
+
+        /* Swap buffers */
+        hashswap (src, dst, tmp);
+        n >>= 1;
+
+        /* Compute all hashes at current layer */
+        hash_compress_pairs (dst, src, n);
+    }
+
+    /* Public key */
+    if (root != NULL) hashcpy (root, dst);
+}
+
+/* Compress node with its auth path on height_diff levels */
+int merkle_compress_auth (struct hash *node, int index, const struct hash *auth, int height_diff) {
+    struct hash buf[2];
+    int l;
+
+    for (l = 0; l < height_diff; ++l) {
+        if (index % 2 == 0) {
+            hashcpy (&buf[0], node);
+            hashcpy (&buf[1], &auth[l]);
+        } else {
+            hashcpy (&buf[0], &auth[l]);
+            hashcpy (&buf[1], node);
+        }
+
+        hash_2N_to_N (node, buf);
+
+        index >>= 1;
+    }
+
+    return index;
+}
+
+void merkle_gen_octopus (struct hash *buf,
+                         int height,
+                         struct hash *octopus,
+                         int *octolen,
+                         struct hash *root,
+                         int *indices,
+                         int count) {
+    int n = 1 << height;
+    struct hash *src = &buf[n];
+    struct hash *dst = &buf[0];
+    struct hash *tmp;
+    int i, j, l;
+    int len = 0;
+    int index, sibling;
+
+    for (l = 0; l < height; ++l) {
+        /* Copy auth octopus */
+        for (i = 0, j = 0; i < count; ++i, ++j) {
+            index = indices[i];
+            sibling = index ^ 1;
+
+            /* Check redundancy with sibling */
+            if (i + 1 < count && indices[i + 1] == sibling)
+                ++i;
+            else
+                hashcpy (&octopus[len++], &dst[sibling]);
+
+            indices[j] = indices[i] >> 1;
+        }
+        /* Update count of non-redundant nodes */
+        count = j;
+
+        /* Swap buffers */
+        hashswap (src, dst, tmp);
+        n >>= 1;
+
+        /* Compute all hashes at current layer */
+        hash_compress_pairs (dst, src, n);
+    }
+
+    hashcpy (root, dst);
+    *octolen = len;
+}
+
+int merkle_compress_octopus (struct hash *nodes,
+                             int height,
+                             const struct hash *octopus,
+                             int octolen,
+                             int *indices,
+                             int count) {
+    struct hash buf[2];
+    int i, j, l;
+    int len = 0;
+    int index;
+
+    for (l = 0; l < height; ++l) {
+        for (i = 0, j = 0; i < count; ++i, ++j) {
+            /* Select 2 values to merge */
+            index = indices[i];
+            if (index % 2 == 0) {
+                hashcpy (&buf[0], &nodes[i]);
+
+                if (i + 1 < count && indices[i + 1] == index + 1) {
+                    ++i;
+                    hashcpy (&buf[1], &nodes[i]);
+                } else {
+                    if (len == octolen) return GRAVITY_ERR_VERIF;
+                    hashcpy (&buf[1], &octopus[len++]);
+                }
+            } else {
+                if (len == octolen) return GRAVITY_ERR_VERIF;
+                hashcpy (&buf[0], &octopus[len++]);
+                hashcpy (&buf[1], &nodes[i]);
+            }
+
+            /* Hash values */
+            hash_2N_to_N (&nodes[j], buf);
+
+            indices[j] = indices[i] >> 1;
+        }
+
+        /* Update count of non-redundant nodes */
+        count = j;
+    }
+
+    /* Check len */
+    if (len != octolen) return GRAVITY_ERR_VERIF;
+
+    return GRAVITY_OK;
+}
diff --git a/crypto/sphincs/merkle.h b/crypto/sphincs/merkle.h
new file mode 100644
index 00000000..e64b0bb2
--- /dev/null
+++ b/crypto/sphincs/merkle.h
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#pragma once
+
+#include "wots.h"
+
+struct merkle_pk {
+    struct hash k;
+};
+
+struct merkle_sign {
+    struct wots_sign wots;
+    struct hash auth[MERKLE_h];
+};
+
+int merkle_genpk (const struct hash *key, const struct address *address, struct merkle_pk *pk);
+
+int merkle_sign (const struct hash *key,
+                 const struct address *address,
+                 struct merkle_sign *sign,
+                 const struct hash *msg,
+                 struct merkle_pk *pk);
+
+void merkle_extract (struct merkle_pk *pk,
+                     const struct address *address,
+                     const struct merkle_sign *sign,
+                     const struct hash *msg);
+
+
+/* Helper functions */
+/* Alloc/free a buffer large enough to store leaves and compress them */
+struct hash *merkle_alloc_buf (int height);
+
+void merkle_free_buf (struct hash *buf);
+
+/* Compress leaves from level height to root */
+void merkle_compress_all (struct hash *buf, int height, struct hash *root);
+
+/* Compute authentication path */
+void merkle_gen_auth (struct hash *buf, int height, struct hash *auth, int index, struct hash *root);
+
+/* Compress node with its auth path on height_diff levels */
+int merkle_compress_auth (struct hash *node, int index, const struct hash *auth, int height_diff);
+
+/* "indices" must be sorted */
+void merkle_gen_octopus (struct hash *buf,
+                         int height,
+                         struct hash *octopus,
+                         int *octolen,
+                         struct hash *root,
+                         int *indices,
+                         int count);
+
+/* Compress a set of leaves with their auth path */
+/* "indices" must be sorted */
+int merkle_compress_octopus (struct hash *nodes,
+                             int height,
+                             const struct hash *octopus,
+                             int octolen,
+                             int *indices,
+                             int count);
diff --git a/crypto/sphincs/pors.c b/crypto/sphincs/pors.c
new file mode 100644
index 00000000..557e695b
--- /dev/null
+++ b/crypto/sphincs/pors.c
@@ -0,0 +1,200 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#include "pors.h"
+
+#include "aes.h"
+#include "merkle.h"
+#include <stdlib.h>
+
+/* Naive PORS without Merkle tree */
+void pors_gensk (const struct hash *key, const struct address *address, struct pors_sk *sk) {
+    uint8_t iv[16];
+
+    iv[0] = (address->index >> 56) & 0xFF;
+    iv[1] = (address->index >> 48) & 0xFF;
+    iv[2] = (address->index >> 40) & 0xFF;
+    iv[3] = (address->index >> 32) & 0xFF;
+    iv[4] = (address->index >> 24) & 0xFF;
+    iv[5] = (address->index >> 16) & 0xFF;
+    iv[6] = (address->index >> 8) & 0xFF;
+    iv[7] = address->index & 0xFF;
+
+    iv[8] = (address->layer >> 24) & 0xFF;
+    iv[9] = (address->layer >> 16) & 0xFF;
+    iv[10] = (address->layer >> 8) & 0xFF;
+    iv[11] = address->layer & 0xFF;
+
+    /* Counter */
+    iv[12] = 0;
+    iv[13] = 0;
+    iv[14] = 0;
+    iv[15] = 0;
+    aesctr256 (sk->k->h, key->h, iv, PORS_t * HASH_SIZE);
+}
+
+void pors_sign (const struct pors_sk *sk, struct pors_sign *sign, const struct pors_subset *subset) {
+    int i;
+    int index;
+
+    for (i = 0; i < PORS_k; ++i) {
+        index = subset->s[i];
+        hashcpy (&sign->s[i], &sk->k[index]);
+    }
+}
+
+
+/* Naive PORST without merging of authentication paths */
+int porst_genpk (const struct pors_sk *sk, struct porst_pk *pk) {
+    struct hash *buf = merkle_alloc_buf (PORS_tau);
+    if (buf == NULL) return GRAVITY_ERR_ALLOC;
+
+    /* Leaves */
+    hash_parallel (buf, sk->k, PORS_t);
+
+    /* Merkle tree */
+    merkle_compress_all (buf, PORS_tau, &pk->k);
+
+    merkle_free_buf (buf);
+    return GRAVITY_OK;
+}
+
+
+/* PORST with authentication octopus */
+void sort_subset (struct pors_subset *subset) {
+    /* Selection sort */
+    int i, j, k, tmp;
+    for (i = 0; i + 1 < PORS_k; ++i) {
+        k = i;
+        tmp = subset->s[k];
+        for (j = i + 1; j < PORS_k; ++j) {
+            if (subset->s[j] < tmp) {
+                k = j;
+                tmp = subset->s[k];
+            }
+        }
+
+        subset->s[k] = subset->s[i];
+        subset->s[i] = tmp;
+    }
+}
+
+int octoporst_sign (const struct pors_sk *sk,
+                    struct octoporst_sign *sign,
+                    struct porst_pk *pk,
+                    struct pors_subset *subset) {
+    struct hash *buf;
+
+    /* Sort subset */
+    sort_subset (subset);
+
+    /* Values */
+    pors_sign (sk, &sign->s, subset);
+
+    /* Authentication paths */
+    buf = merkle_alloc_buf (PORS_tau);
+    if (buf == NULL) return GRAVITY_ERR_ALLOC;
+
+    /* Leaves */
+    hash_parallel (buf, sk->k, PORS_t);
+
+    /* Merkle tree */
+    merkle_gen_octopus (buf, PORS_tau, sign->octopus, &sign->octolen, &pk->k,
+                        subset->s, PORS_k);
+
+    merkle_free_buf (buf);
+    return GRAVITY_OK;
+}
+
+int octoporst_extract (struct porst_pk *pk,
+                       const struct octoporst_sign *sign,
+                       struct pors_subset *subset) {
+    struct hash tmp[PORS_k];
+    int res;
+
+    /* Sort subset */
+    sort_subset (subset);
+
+    /* Compute leaves */
+    hash_parallel (tmp, sign->s.s, PORS_k);
+
+    /* Auth octopus */
+    res = merkle_compress_octopus (tmp, PORS_tau, sign->octopus, sign->octolen,
+                                   subset->s, PORS_k);
+    if (res != GRAVITY_OK) return res;
+
+    hashcpy (&pk->k, &tmp[0]);
+    return GRAVITY_OK;
+}
+
+
+int octoporst_loadsign (struct octoporst_sign *sign, const uint8_t *_sign, size_t _len) {
+    if (_len < sizeof (struct pors_sign)) return GRAVITY_ERR_VERIF;
+    _len -= sizeof (struct pors_sign);
+
+    if (_len % HASH_SIZE != 0) return GRAVITY_ERR_VERIF;
+    _len /= HASH_SIZE;
+
+    if (_len > PORS_k * PORS_tau) return GRAVITY_ERR_VERIF;
+
+    memcpy (&sign->s, _sign, sizeof (struct pors_sign));
+    _sign += sizeof (struct pors_sign);
+    memcpy (sign->octopus, _sign, _len * HASH_SIZE);
+    sign->octolen = _len;
+
+    return GRAVITY_OK;
+}
+
+int octoporst_signcmp (const struct octoporst_sign *sign1,
+                       const struct octoporst_sign *sign2) {
+    if (sign1->octolen != sign2->octolen) return 1;
+    if (hashcmpN (sign1->s.s, sign2->s.s, PORS_k)) return 1;
+    if (hashcmpN (sign1->octopus, sign2->octopus, sign1->octolen)) return 1;
+
+    return 0;
+}
+
+
+void pors_randsubset (const struct hash *rand,
+                      const struct hash *msg,
+                      uint64_t *address,
+                      struct pors_subset *subset) {
+#define BYTES_PER_INDEX 4
+#define STREAMLEN                                                              \
+    ((8 * (PORS_k)) + HASH_SIZE) /* count twice as many indexes as needed */
+    uint8_t randstream[STREAMLEN];
+    int index, duplicate, i, count = 0;
+    size_t offset = 0;
+    struct hash seed;
+    struct hash buf[2];
+    uint64_t addr;
+    uint8_t byte;
+
+    hashcpy (&buf[0], rand);
+    hashcpy (&buf[1], msg);
+    hash_2N_to_N (&seed, buf);
+
+    aesctr256_zeroiv (randstream, seed.h, STREAMLEN);
+
+    /* compute address */
+    addr = 0;
+    for (i = 0; i < HASH_SIZE; ++i) {
+        byte = randstream[i];
+        addr = (addr << 8) | byte;
+        addr &= GRAVITY_mask;
+    }
+    *address = addr;
+
+    while (count < PORS_k) {
+        /* ok to take mod since T is a power of 2 */
+        index = U8TO32 (randstream + HASH_SIZE + offset) % PORS_t;
+        offset += BYTES_PER_INDEX;
+        duplicate = 0;
+        for (i = 0; i < count; ++i)
+            if (subset->s[i] == index) duplicate++;
+        if (!duplicate) {
+            subset->s[count] = index;
+            count++;
+        }
+    }
+}
diff --git a/crypto/sphincs/pors.h b/crypto/sphincs/pors.h
new file mode 100644
index 00000000..15be8af9
--- /dev/null
+++ b/crypto/sphincs/pors.h
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#pragma once
+
+#include "hash.h"
+
+/* PRNG to obtain a random subset */
+struct pors_subset {
+    int s[PORS_k];
+};
+
+void pors_randsubset (const struct hash *rand,
+                      const struct hash *msg,
+                      uint64_t *address,
+                      struct pors_subset *subset);
+
+
+/* Naive PORS without Merkle tree */
+struct pors_sk {
+    struct hash k[PORS_t];
+};
+
+struct pors_pk {
+    struct hash k[PORS_t];
+};
+
+struct pors_keypair {
+    struct pors_sk sk;
+    struct pors_pk pk;
+};
+
+struct pors_sign {
+    struct hash s[PORS_k];
+};
+
+void pors_gensk (const struct hash *key, const struct address *address, struct pors_sk *sk);
+
+void pors_sign (const struct pors_sk *sk, struct pors_sign *sign, const struct pors_subset *subset);
+
+
+/* Naive PORST without merging of authentication paths */
+struct porst_pk {
+    struct hash k;
+};
+
+struct porst_keypair {
+    struct pors_sk sk;
+    struct porst_pk pk;
+};
+
+int porst_genpk (const struct pors_sk *sk, struct porst_pk *pk);
+
+
+/* PORST with authentication octopus */
+struct octoporst_sign {
+    struct pors_sign s;
+    struct hash octopus[PORS_k * PORS_tau]; /* Large enough buffer */
+    int octolen; /* Number of elements in the octopus */
+};
+
+int octoporst_sign (const struct pors_sk *sk,
+                    struct octoporst_sign *sign,
+                    struct porst_pk *pk,
+                    struct pors_subset *subset);
+
+int octoporst_extract (struct porst_pk *pk,
+                       const struct octoporst_sign *sign,
+                       struct pors_subset *subset);
+
+/* Serialization */
+int octoporst_loadsign (struct octoporst_sign *sign, const uint8_t *_sign, size_t _len);
+
+int octoporst_signcmp (const struct octoporst_sign *sign1, const struct octoporst_sign *sign2);
diff --git a/crypto/sphincs/primitives/aes.c b/crypto/sphincs/primitives/aes.c
new file mode 100644
index 00000000..cbda47f1
--- /dev/null
+++ b/crypto/sphincs/primitives/aes.c
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+
+#include "../aes.h"
+#include <openssl/conf.h>
+#include <openssl/err.h>
+#include <openssl/evp.h>
+#include <stdio.h>
+#include <string.h>
+
+
+int aesctr256 (uint8_t *out, const uint8_t *sk, const void *counter, int bytes) {
+    static const uint8_t buffer[4096] = { 0 };
+    EVP_CIPHER_CTX *ctx;
+    int len = 0;
+    int ret = 0;
+
+    if (bytes == 0) return 0;
+
+    if (!(ctx = EVP_CIPHER_CTX_new ())) {
+        ret = -2;
+        goto label_exit_0;
+    }
+
+    if (1 != EVP_EncryptInit_ex (ctx, EVP_aes_256_ctr (), NULL, sk, counter)) {
+        ret = -3;
+        goto label_exit_1;
+    }
+
+    while (bytes >= (int)sizeof (buffer)) {
+        if (1 != EVP_EncryptUpdate (ctx, out, &len, buffer, sizeof (buffer))) {
+            ret = -4;
+            goto label_exit_1;
+        }
+        out += sizeof (buffer);
+        bytes -= sizeof (buffer);
+    }
+    if (bytes) {
+        if (1 != EVP_EncryptUpdate (ctx, out, &len, buffer, bytes)) {
+            ret = -4;
+            goto label_exit_1;
+        }
+    }
+
+    if (1 != EVP_EncryptFinal_ex (ctx, out + len, &len)) {
+        ret = -5;
+        goto label_exit_1;
+    }
+
+    ret = 0;
+label_exit_1:
+    EVP_CIPHER_CTX_free (ctx);
+label_exit_0:
+    return ret;
+}
+
+int aesctr256_zeroiv (uint8_t *out, const uint8_t *sk, int bytes) {
+    uint8_t counter[16] = {0};
+    return aesctr256(out, sk, counter, bytes);
+}
diff --git a/crypto/sphincs/primitives/haraka.c b/crypto/sphincs/primitives/haraka.c
new file mode 100644
index 00000000..08f4b24a
--- /dev/null
+++ b/crypto/sphincs/primitives/haraka.c
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+
+#include "haraka.h"
+#include <string.h>
+
+
+void aesenc (uint8_t *s, const uint8_t *rk) {
+    uint8_t i, t, u, v[4][4];
+    for (i = 0; i < 16; ++i) v[((i / 4) + 4 - (i % 4)) % 4][i % 4] = sbox[s[i]];
+    for (i = 0; i < 4; ++i) {
+        t = v[i][0];
+        u = v[i][0] ^ v[i][1] ^ v[i][2] ^ v[i][3];
+        v[i][0] ^= u ^ XT (v[i][0] ^ v[i][1]);
+        v[i][1] ^= u ^ XT (v[i][1] ^ v[i][2]);
+        v[i][2] ^= u ^ XT (v[i][2] ^ v[i][3]);
+        v[i][3] ^= u ^ XT (v[i][3] ^ t);
+    }
+    for (i = 0; i < 16; ++i) s[i] = v[i / 4][i % 4] ^ rk[i];
+}
+
+
+void haraka256_256 (uint8_t *out, const uint8_t *in) {
+
+    uint8_t s0[16], s1[16];
+    uint32_t tmp[4];
+    int i;
+
+    memcpy (s0, in, 16);
+    memcpy (s1, in + 16, 16);
+
+    AES2 (0);
+    MIX2;
+    AES2 (4);
+    MIX2;
+    AES2 (8);
+    MIX2;
+    AES2 (12);
+    MIX2;
+    AES2 (16);
+    MIX2;
+    AES2 (20);
+    MIX2;
+
+    for (i = 0; i < 16; ++i) {
+        out[i] = in[i] ^ s0[i];
+        out[i + 16] = in[i + 16] ^ s1[i];
+    }
+}
+
+void haraka256_256_chain (uint8_t *out, const uint8_t *in, int chainlen) {
+
+    uint8_t s0[16], s1[16];
+    uint8_t t0[16], t1[16];
+    uint32_t tmp[4];
+    int i, j;
+
+    memcpy (s0, in, 16);
+    memcpy (s1, in + 16, 16);
+    memcpy (t0, in, 16);
+    memcpy (t1, in + 16, 16);
+
+    for (j = 0; j < chainlen; ++j) {
+
+        AES2 (0);
+        MIX2;
+        AES2 (4);
+        MIX2;
+        AES2 (8);
+        MIX2;
+        AES2 (12);
+        MIX2;
+        AES2 (16);
+        MIX2;
+        AES2 (20);
+        MIX2;
+
+        for (i = 0; i < 16; ++i) {
+            s0[i] = t0[i] = t0[i] ^ s0[i];
+            s1[i] = t1[i] = t1[i] ^ s1[i];
+        }
+    }
+    for (i = 0; i < 16; ++i) {
+        out[i] = s0[i];
+        out[i + 16] = s1[i];
+    }
+}
+
+void haraka512_256 (uint8_t *out, const uint8_t *in) {
+
+    uint8_t s0[16], s1[16], s2[16], s3[16];
+    uint32_t tmp[5];
+    int i;
+
+    memcpy (s0, in, 16);
+    memcpy (s1, in + 16, 16);
+    memcpy (s2, in + 32, 16);
+    memcpy (s3, in + 48, 16);
+
+    AES4 (0);
+    MIX4;
+    AES4 (8);
+    MIX4;
+    AES4 (16);
+    MIX4;
+    AES4 (24);
+    MIX4;
+    AES4 (32);
+    MIX4;
+    AES4 (40);
+    MIX4;
+
+    for (i = 0; i < 16; ++i) {
+        s0[i] = in[i] ^ s0[i];
+        s1[i] = in[i + 16] ^ s1[i];
+        s2[i] = in[i + 32] ^ s2[i];
+        s3[i] = in[i + 48] ^ s3[i];
+    }
+
+    ((uint64_t *)out)[0] = ((uint64_t *)s0)[1];
+    ((uint64_t *)out)[1] = ((uint64_t *)s1)[1];
+    ((uint64_t *)out)[2] = ((uint64_t *)s2)[0];
+    ((uint64_t *)out)[3] = ((uint64_t *)s3)[0];
+}
diff --git a/crypto/sphincs/primitives/haraka.h b/crypto/sphincs/primitives/haraka.h
new file mode 100644
index 00000000..cb5c5057
--- /dev/null
+++ b/crypto/sphincs/primitives/haraka.h
@@ -0,0 +1,160 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 Stefan Kölbl
+original Haraka implementations
+
+Copyright (c) 2017 Nagravision S.A.
+changes by JP Aumasson, Guillaume Endignoux, 2017: improvements, non-ni versions
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+ */
+#pragma once
+
+
+#include <stdint.h>
+
+
+static const uint32_t rc[48 * 4] = {
+    0x75817b9d, 0xb2c5fef0, 0xe620c00a, 0x0684704c, 0x2f08f717, 0x640f6ba4,
+    0x88f3a06b, 0x8b66b4e1, 0x9f029114, 0xcf029d60, 0x53f28498, 0x3402de2d,
+    0xfd5b4f79, 0xbbf3bcaf, 0x2e7b4f08, 0x0ed6eae6, 0xbe397044, 0x79eecd1c,
+    0x4872448b, 0xcbcfb0cb, 0x2b8a057b, 0x8d5335ed, 0x6e9032b7, 0x7eeacdee,
+    0xda4fef1b, 0xe2412761, 0x5e2e7cd0, 0x67c28f43, 0x1fc70b3b, 0x675ffde2,
+    0xafcacc07, 0x2924d9b0, 0xb9d465ee, 0xecdb8fca, 0xe6867fe9, 0xab4d63f1,
+    0xad037e33, 0x5b2a404f, 0xd4b7cd64, 0x1c30bf84, 0x8df69800, 0x69028b2e,
+    0x941723bf, 0xb2cc0bb9, 0x5c9d2d8a, 0x4aaa9ec8, 0xde6f5572, 0xfa0478a6,
+    0x29129fd4, 0x0efa4f2e, 0x6b772a12, 0xdfb49f2b, 0xbb6a12ee, 0x32d611ae,
+    0xf449a236, 0x1ea10344, 0x9ca8eca6, 0x5f9600c9, 0x4b050084, 0xaf044988,
+    0x27e593ec, 0x78a2c7e3, 0x9d199c4f, 0x21025ed8, 0x82d40173, 0xb9282ecd,
+    0xa759c9b7, 0xbf3aaaf8, 0x10307d6b, 0x37f2efd9, 0x6186b017, 0x6260700d,
+    0xf6fc9ac6, 0x81c29153, 0x21300443, 0x5aca45c2, 0x36d1943a, 0x2caf92e8,
+    0x226b68bb, 0x9223973c, 0xe51071b4, 0x6cbab958, 0x225886eb, 0xd3bf9238,
+    0x24e1128d, 0x933dfddd, 0xaef0c677, 0xdb863ce5, 0xcb2212b1, 0x83e48de3,
+    0xffeba09c, 0xbb606268, 0xc72bf77d, 0x2db91a4e, 0xe2e4d19c, 0x734bd3dc,
+    0x2cb3924e, 0x4b1415c4, 0x61301b43, 0x43bb47c3, 0x16eb6899, 0x03b231dd,
+    0xe707eff6, 0xdba775a8, 0x7eca472c, 0x8e5e2302, 0x3c755977, 0x6df3614b,
+    0xb88617f9, 0x6d1be5b9, 0xd6de7d77, 0xcda75a17, 0xa946ee5d, 0x9d6c069d,
+    0x6ba8e9aa, 0xec6b43f0, 0x3bf327c1, 0xa2531159, 0xf957332b, 0xcb1e6950,
+    0x600ed0d9, 0xe4ed0353, 0x00da619c, 0x2cee0c75, 0x63a4a350, 0x80bbbabc,
+    0x96e90cab, 0xf0b1a5a1, 0x938dca39, 0xab0dde30, 0x5e962988, 0xae3db102,
+    0x2e75b442, 0x8814f3a8, 0xd554a40b, 0x17bb8f38, 0x360a16f6, 0xaeb6b779,
+    0x5f427fd7, 0x34bb8a5b, 0xffbaafde, 0x43ce5918, 0xcbe55438, 0x26f65241,
+    0x839ec978, 0xa2ca9cf7, 0xb9f3026a, 0x4ce99a54, 0x22901235, 0x40c06e28,
+    0x1bdff7be, 0xae51a51a, 0x48a659cf, 0xc173bc0f, 0xba7ed22b, 0xa0c1613c,
+    0xe9c59da1, 0x4ad6bdfd, 0x02288288, 0x756acc03, 0x848f2ad2, 0x367e4778,
+    0x0de7d31e, 0x2ff37238, 0xb73bd58f, 0xee36b135, 0xcf74be8b, 0x08d95c6a,
+    0xa3743e4a, 0x66ae1838, 0xc9d6ee98, 0x5880f434, 0x9a9369bd, 0xd0fdf4c7,
+    0xaefabd99, 0x593023f0, 0x6f1ecb2a, 0xa5cc637b, 0xeb606e6f, 0x329ae3d1,
+    0xcb7594ab, 0xa4dc93d6, 0x49e01594, 0xe00207eb, 0x65208ef8, 0x942366a6,
+    0xf751c880, 0x1caa0c4f, 0xe3e67e4a, 0xbd03239f, 0xdb2dc1dd, 0x02f7f57f,
+};
+
+static const uint8_t sbox[256] =
+{ 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe,
+  0xd7, 0xab, 0x76, 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4,
+  0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7,
+  0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, 0x04, 0xc7, 0x23, 0xc3,
+  0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, 0x09,
+  0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3,
+  0x2f, 0x84, 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe,
+  0x39, 0x4a, 0x4c, 0x58, 0xcf, 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85,
+  0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92,
+  0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, 0xcd, 0x0c,
+  0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19,
+  0x73, 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14,
+  0xde, 0x5e, 0x0b, 0xdb, 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2,
+  0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5,
+  0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, 0xba, 0x78, 0x25,
+  0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
+  0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86,
+  0xc1, 0x1d, 0x9e, 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e,
+  0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42,
+  0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 };
+
+#define XT(x) (((x) << 1) ^ ((((x) >> 7) & 1) * 0x1b))
+
+#define AES2(rci)                                                              \
+    aesenc (s0, ((uint8_t *)rc) + 16 * (rci + 0));                             \
+    aesenc (s1, ((uint8_t *)rc) + 16 * (rci + 1));                             \
+    aesenc (s0, ((uint8_t *)rc) + 16 * (rci + 2));                             \
+    aesenc (s1, ((uint8_t *)rc) + 16 * (rci + 3));
+
+#define MIX2                                                                   \
+    tmp[0] = ((uint32_t *)s0)[0];                                              \
+    tmp[1] = ((uint32_t *)s1)[0];                                              \
+    tmp[2] = ((uint32_t *)s0)[1];                                              \
+    tmp[3] = ((uint32_t *)s1)[1];                                              \
+    ((uint32_t *)s1)[0] = ((uint32_t *)s0)[2];                                 \
+    ((uint32_t *)s1)[1] = ((uint32_t *)s1)[2];                                 \
+    ((uint32_t *)s1)[2] = ((uint32_t *)s0)[3];                                 \
+    ((uint32_t *)s0)[0] = tmp[0];                                              \
+    ((uint32_t *)s0)[1] = tmp[1];                                              \
+    ((uint32_t *)s0)[2] = tmp[2];                                              \
+    ((uint32_t *)s0)[3] = tmp[3];
+
+#define AES4(rci)                                                              \
+    aesenc (s0, ((uint8_t *)rc) + 16 * (rci + 0));                             \
+    aesenc (s1, ((uint8_t *)rc) + 16 * (rci + 1));                             \
+    aesenc (s2, ((uint8_t *)rc) + 16 * (rci + 2));                             \
+    aesenc (s3, ((uint8_t *)rc) + 16 * (rci + 3));                             \
+    aesenc (s0, ((uint8_t *)rc) + 16 * (rci + 4));                             \
+    aesenc (s1, ((uint8_t *)rc) + 16 * (rci + 5));                             \
+    aesenc (s2, ((uint8_t *)rc) + 16 * (rci + 6));                             \
+    aesenc (s3, ((uint8_t *)rc) + 16 * (rci + 7));
+
+#define MIX4                                                                   \
+    tmp[0] = ((uint32_t *)s0)[0];                                              \
+    tmp[1] = ((uint32_t *)s1)[0];                                              \
+    tmp[2] = ((uint32_t *)s0)[1];                                              \
+    tmp[3] = ((uint32_t *)s1)[1];                                              \
+    tmp[4] = ((uint32_t *)s3)[0];                                              \
+    ((uint32_t *)s0)[0] = ((uint32_t *)s0)[2];                                 \
+    ((uint32_t *)s0)[1] = ((uint32_t *)s1)[2];                                 \
+    ((uint32_t *)s0)[2] = ((uint32_t *)s0)[3];                                 \
+    ((uint32_t *)s0)[3] = ((uint32_t *)s1)[3];                                 \
+    ((uint32_t *)s1)[0] = ((uint32_t *)s2)[0];                                 \
+    ((uint32_t *)s1)[1] = ((uint32_t *)s3)[0];                                 \
+    ((uint32_t *)s1)[2] = ((uint32_t *)s2)[1];                                 \
+    ((uint32_t *)s1)[3] = ((uint32_t *)s3)[1];                                 \
+    ((uint32_t *)s2)[0] = ((uint32_t *)s2)[2];                                 \
+    ((uint32_t *)s2)[1] = ((uint32_t *)s3)[2];                                 \
+    ((uint32_t *)s2)[2] = ((uint32_t *)s2)[3];                                 \
+    ((uint32_t *)s2)[3] = ((uint32_t *)s3)[3];                                 \
+    ((uint32_t *)s3)[0] = ((uint32_t *)s0)[0];                                 \
+    ((uint32_t *)s3)[1] = ((uint32_t *)s2)[0];                                 \
+    ((uint32_t *)s3)[2] = ((uint32_t *)s0)[1];                                 \
+    ((uint32_t *)s3)[3] = ((uint32_t *)s2)[1];                                 \
+    ((uint32_t *)s0)[0] = ((uint32_t *)s0)[2];                                 \
+    ((uint32_t *)s0)[1] = ((uint32_t *)s2)[2];                                 \
+    ((uint32_t *)s0)[2] = ((uint32_t *)s0)[3];                                 \
+    ((uint32_t *)s0)[3] = ((uint32_t *)s2)[3];                                 \
+    ((uint32_t *)s2)[0] = ((uint32_t *)s1)[2];                                 \
+    ((uint32_t *)s2)[1] = tmp[2];                                              \
+    ((uint32_t *)s2)[2] = ((uint32_t *)s1)[3];                                 \
+    ((uint32_t *)s2)[3] = tmp[3];                                              \
+    ((uint32_t *)s1)[0] = ((uint32_t *)s1)[0];                                 \
+    ((uint32_t *)s1)[1] = tmp[0];                                              \
+    ((uint32_t *)s1)[2] = tmp[4];                                              \
+    ((uint32_t *)s1)[3] = tmp[1];
+
+
+void haraka256_256(unsigned char *out, const unsigned char *in);
+void haraka256_256_chain(unsigned char *out, const unsigned char *in, int chainlen);
+void haraka512_256(unsigned char *out, const unsigned char *in);
diff --git a/crypto/sphincs/primitives/hash.c b/crypto/sphincs/primitives/hash.c
new file mode 100644
index 00000000..7b990083
--- /dev/null
+++ b/crypto/sphincs/primitives/hash.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#include "../hash.h"
+
+#include "haraka.h"
+#include <openssl/sha.h>
+
+void hash_N_to_N(struct hash *dst, const struct hash *src)
+{
+    haraka256_256(dst->h, src->h);
+}
+
+void hash_N_to_N_chain(struct hash *dst, const struct hash *src, int chainlen)
+{
+    haraka256_256_chain(dst->h, src->h, chainlen);
+}
+
+void hash_2N_to_N(struct hash *dst, const struct hash *src)
+{
+    haraka512_256(dst->h, src->h);
+}
+
+void hash_to_N(struct hash *dst, const uint8_t *src, uint64_t srclen)
+{
+    SHA256(src, srclen, dst->h);
+}
+
+void hash_compress_pairs(struct hash *dst, const struct hash *src, int count)
+{
+    int i = 0;
+    for (; i < count; ++i)
+        hash_2N_to_N(&dst[i], &src[2*i]);
+}
+
+void hash_compress_all(struct hash *dst, const struct hash *src, int count)
+{
+    /* Fast implementation with a single call to a large input hash function */
+    hash_to_N(dst, src->h, count * HASH_SIZE);
+    /* TODO: implement a real L-tree with 2N->N compression function */
+}
+
+void hash_parallel(struct hash *dst, const struct hash *src, int count)
+{
+    int i = 0;
+    for (; i < count; ++i)
+        hash_N_to_N(&dst[i], &src[i]);
+}
+
+void hash_parallel_chains(struct hash *dst, const struct hash *src, int count, int chainlen)
+{
+    int i = 0;
+    for (; i < count; ++i)
+        hash_N_to_N_chain(&dst[i], &src[i], chainlen);
+}
+
diff --git a/crypto/sphincs/randombytes.c b/crypto/sphincs/randombytes.c
new file mode 100644
index 00000000..904daf41
--- /dev/null
+++ b/crypto/sphincs/randombytes.c
@@ -0,0 +1,13 @@
+#include "randombytes.h"
+
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+/* lazy unsafe emulation of SUPERCOP's randombytes() */
+void randombytes (unsigned char *x, unsigned long long xlen) {
+    static int fd = -1;
+    if (fd == -1) fd = open ("/dev/urandom", O_RDONLY);
+    read (fd, x, xlen);
+}
diff --git a/crypto/sphincs/randombytes.h b/crypto/sphincs/randombytes.h
new file mode 100644
index 00000000..77d6f648
--- /dev/null
+++ b/crypto/sphincs/randombytes.h
@@ -0,0 +1,4 @@
+#pragma once
+
+void randombytes (unsigned char *x, unsigned long long xlen);
+
diff --git a/crypto/sphincs/sign.c b/crypto/sphincs/sign.c
new file mode 100644
index 00000000..c656fea7
--- /dev/null
+++ b/crypto/sphincs/sign.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#include "gravity.h"
+#include "randombytes.h"
+
+
+int crypto_sign_keypair (unsigned char *pk, unsigned char *sk) {
+
+    struct gravity_sk sk_str;
+    struct gravity_pk pk_str;
+
+    if (!pk || !sk) return -1;
+
+    randombytes (sk_str.seed.h, HASH_SIZE);
+    randombytes (sk_str.salt.h, HASH_SIZE);
+
+    gravity_gensk (&sk_str);
+
+    memcpy (sk, (void *)&sk_str, sizeof (struct gravity_sk));
+
+    gravity_genpk (&sk_str, &pk_str);
+
+    memcpy (pk, pk_str.k.h, HASH_SIZE);
+
+    return 0;
+}
+
+int crypto_sign (unsigned char *sm,
+                 unsigned long long *smlen,
+                 const unsigned char *m,
+                 unsigned long long mlen,
+                 const unsigned char *sk) {
+
+    struct gravity_sk sk_str;
+    struct hash msg;
+    struct gravity_sign sig;
+    int ret;
+
+    if (!sm || !smlen || !m || !sk) return -1;
+
+    hash_to_N (&msg, m, mlen);
+
+    memcpy ((void *)&sk_str, sk, sizeof (struct gravity_sk));
+
+    memset ((uint8_t *)(&sig), 0, sizeof (struct gravity_sign));
+
+    ret = gravity_sign (&sk_str, &sig, &msg);
+
+    if (ret != GRAVITY_OK) return ret;
+
+    memcpy (sm + mlen, (uint8_t *)(&sig), sizeof (struct gravity_sign));
+
+    memmove (sm, m, mlen);
+    *smlen = mlen + sizeof (struct gravity_sign);
+
+    return 0;
+}
+
+int crypto_sign_open (unsigned char *m,
+                      unsigned long long *mlen,
+                      const unsigned char *sm,
+                      unsigned long long smlen,
+                      const unsigned char *pk) {
+
+    struct gravity_pk pk_str;
+    struct hash msg;
+    struct gravity_sign sig;
+
+    if (!m || !mlen || !sm || !pk) return -1;
+
+    if (smlen < sizeof (struct gravity_sign)) return -2;
+
+    *mlen = smlen - sizeof (struct gravity_sign);
+
+    memcpy ((void *)(&pk_str), pk, HASH_SIZE);
+
+    memcpy ((void *)&sig, sm + *mlen, sizeof (struct gravity_sign));
+
+    memcpy (m, sm, *mlen);
+
+    hash_to_N (&msg, m, *mlen);
+
+    return gravity_verify (&pk_str, &sig, &msg);
+}
diff --git a/crypto/sphincs/sign.h b/crypto/sphincs/sign.h
new file mode 100644
index 00000000..111427b5
--- /dev/null
+++ b/crypto/sphincs/sign.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#pragma once
+
+int crypto_sign_keypair (unsigned char *pk, unsigned char *sk);
+
+int crypto_sign (unsigned char *sm,
+                 unsigned long long *smlen,
+                 const unsigned char *m,
+                 unsigned long long mlen,
+                 const unsigned char *sk);
+
+int crypto_sign_open (unsigned char *m,
+                      unsigned long long *mlen,
+                      const unsigned char *sm,
+                      unsigned long long smlen,
+                      const unsigned char *pk);
diff --git a/crypto/sphincs/wots.c b/crypto/sphincs/wots.c
new file mode 100644
index 00000000..5aa014fd
--- /dev/null
+++ b/crypto/sphincs/wots.c
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#include "wots.h"
+#include "aes.h"
+
+#include "ltree.h"
+
+void wots_chain (const struct hash *src, struct hash *dst, int count) {
+    hash_N_to_N_chain (dst, src, count);
+}
+
+/* Naive WOTS without L-tree nor masks */
+void wots_gensk (const struct hash *key, const struct address *address, struct wots_sk *sk) {
+    uint8_t iv[16];
+
+    iv[0] = (address->index >> 56) & 0xFF;
+    iv[1] = (address->index >> 48) & 0xFF;
+    iv[2] = (address->index >> 40) & 0xFF;
+    iv[3] = (address->index >> 32) & 0xFF;
+    iv[4] = (address->index >> 24) & 0xFF;
+    iv[5] = (address->index >> 16) & 0xFF;
+    iv[6] = (address->index >> 8) & 0xFF;
+    iv[7] = address->index & 0xFF;
+
+    iv[8] = (address->layer >> 24) & 0xFF;
+    iv[9] = (address->layer >> 16) & 0xFF;
+    iv[10] = (address->layer >> 8) & 0xFF;
+    iv[11] = address->layer & 0xFF;
+
+    /* Counter */
+    iv[12] = 0;
+    iv[13] = 0;
+    iv[14] = 0;
+    iv[15] = 0;
+    aesctr256 (sk->k->h, key->h, iv, WOTS_ell * HASH_SIZE);
+}
+
+void wots_sign (const struct wots_sk *sk, struct wots_sign *sign, const struct hash *msg) {
+    int checksum = 0;
+    int i;
+
+    for (i = 0; i < WOTS_ell1; ++i) {
+        uint8_t v = msg->h[i / 2];
+        int a = (v >> 4) & 15;
+        int b = v & 15;
+        checksum += (WOTS_w - 1 - a) + (WOTS_w - 1 - b);
+
+        wots_chain (&sk->k[i], &sign->s[i], a);
+        ++i;
+        wots_chain (&sk->k[i], &sign->s[i], b);
+    }
+
+    /* Checksum values */
+    for (i = WOTS_ell1; i < WOTS_ell; ++i) {
+        wots_chain (&sk->k[i], &sign->s[i], checksum & 15);
+        checksum >>= 4;
+    }
+}
+
+
+/* WOTS with L-tree and without masks */
+void lwots_ltree (const struct wots_pk *pk, struct lwots_pk *root) {
+    struct hash buf[2 * WOTS_ell];
+
+    hashcpyN (buf, pk->k, WOTS_ell);
+    ltree (buf, WOTS_ell, &root->k);
+}
+
+void lwots_genpk (const struct wots_sk *sk, struct lwots_pk *pk) {
+    struct wots_pk tmp;
+
+    hash_parallel_chains (tmp.k, sk->k, WOTS_ell, WOTS_w - 1);
+    lwots_ltree (&tmp, pk);
+}
+
+void lwots_extract (struct lwots_pk *pk, const struct wots_sign *sign, const struct hash *msg) {
+    struct wots_pk tmp;
+    int i;
+    int checksum = 0;
+
+    for (i = 0; i < WOTS_ell1; ++i) {
+        uint8_t v = msg->h[i / 2];
+        int a = (v >> 4) & 15;
+        int b = v & 15;
+        checksum += (WOTS_w - 1 - a) + (WOTS_w - 1 - b);
+
+        wots_chain (&sign->s[i], &tmp.k[i], WOTS_w - 1 - a);
+        ++i;
+        wots_chain (&sign->s[i], &tmp.k[i], WOTS_w - 1 - b);
+    }
+
+    /* Checksum values */
+    for (i = WOTS_ell1; i < WOTS_ell; ++i) {
+        wots_chain (&sign->s[i], &tmp.k[i], WOTS_w - 1 - (checksum & 15));
+        checksum >>= 4;
+    }
+
+    /* L-tree */
+    lwots_ltree (&tmp, pk);
+}
diff --git a/crypto/sphincs/wots.h b/crypto/sphincs/wots.h
new file mode 100644
index 00000000..dd4a7fbd
--- /dev/null
+++ b/crypto/sphincs/wots.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2017 Nagravision S.A.
+ */
+#pragma once
+
+#include "common.h"
+#include "hash.h"
+
+/* Naive WOTS without L-tree nor masks */
+struct wots_sk {
+    struct hash k[WOTS_ell];
+};
+
+struct wots_pk {
+    struct hash k[WOTS_ell];
+};
+
+struct wots_sign {
+    struct hash s[WOTS_ell];
+};
+
+void wots_gensk (const struct hash *key, const struct address *address, struct wots_sk *sk);
+
+void wots_sign (const struct wots_sk *sk, struct wots_sign *sign, const struct hash *msg);
+
+
+/* WOTS with L-tree and without masks */
+struct lwots_pk {
+    struct hash k;
+};
+
+void lwots_genpk (const struct wots_sk *sk, struct lwots_pk *pk);
+
+void lwots_extract (struct lwots_pk *pk, const struct wots_sign *sign, const struct hash *msg);