DIPPE scheme (#12)

CMakeLists.txt

@@ -30,6 +30,7 @@ include_directories(
 # Library sources
 set(library_SOURCES
         src/data/mat.c
+        src/data/mat_curve.c
         src/data/vec.c
         src/data/vec_float.c
         src/data/vec_curve.c
@@ -56,6 +57,7 @@ set(library_SOURCES
         src/abe/policy.c
         src/abe/gpsw.c
         src/abe/fame.c
+        src/abe/dippe.c
         src/quadratic/sgp.c
         )
 
@@ -93,6 +95,7 @@ set(binary_SOURCES
         test/abe/policy.c
         test/abe/gpsw.c
         test/abe/fame.c
+        test/abe/dippe.c
         external/munit/munit.c
         test/quadratic/sgp.c
         )

include/cifer/abe/dippe.h

@@ -0,0 +1,243 @@
+/*
+ * Copyright (c) 2018 XLAB d.o.o.
+ *
+ * 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.
+ */
+
+#ifndef CIFER_DIPPE_H
+#define CIFER_DIPPE_H
+
+#include <amcl/ecp2_BN254.h>
+#include <amcl/fp12_BN254.h>
+#include <gmp.h>
+#include <stdlib.h>
+
+#include "cifer/data/mat.h"
+#include "cifer/data/mat_curve.h"
+#include "cifer/data/vec.h"
+#include "cifer/data/vec_curve.h"
+#include "cifer/internal/errors.h"
+
+/**
+* \file
+* \ingroup abe
+* \brief This is a decentralized inner-product predicate encryption
+* scheme by Yan Michalevsky and Marc Joye: "Decentralized Policy-Hiding
+* Attribute-Based Encryption with Receiver Privacy"
+*/
+
+/**
+ * cfe_dippe represents the DIPPE scheme
+ */
+typedef struct cfe_dippe {
+    size_t assump_size;
+    mpz_t p;
+    cfe_mat_G1 g1_A;
+    cfe_mat_G1 g1_UA;
+} cfe_dippe;
+
+/**
+ * Initializes the DIPPE scheme and generates the global parameters
+ *
+ * @param dippe A pointer to a cfe_dippe struct
+ * @param assump_size The size of the underlying assumption
+ */
+void cfe_dippe_init(cfe_dippe *dippe, size_t assump_size);
+
+/**
+ * Clears the scheme and frees allocated memory
+ *
+ * @param dippe A pointer to a cfe_dippe struct
+ */
+void cfe_dippe_free(cfe_dippe *dippe);
+
+/**
+ * Prepares an attribute vector
+ *
+ * @param av A pointer to a cfe_vec struct; Represents the resulting attribute vector
+ * @param num_attrib Number of attributes
+ * @param pattern Array of indices to define the attribute vector
+ * @param pat_len Length of the pattern array
+ * @return Error code
+ */
+cfe_error cfe_dippe_attribute_vector_init(cfe_vec *av, size_t num_attrib, size_t pattern[], size_t pat_len);
+
+/**
+ * Prepares an exact threshold policy vector
+ *
+ * @param pv A pointer to a cfe_vec struct; Represents the resulting policy vector
+ * @param dippe A pointer to a cfe_dippe struct
+ * @param num_attrib Number of attributes
+ * @param pattern Array of indices to define the policy vector
+ * @param pat_len Length of the pattern array
+ * @param threshold Threshold value
+ * @return Error code
+ */
+cfe_error cfe_dippe_exact_threshold_policy_vector_init(cfe_vec *pv, cfe_dippe *dippe, size_t num_attrib, size_t pattern[], size_t pat_len, size_t threshold);
+
+/**
+ * Prepares a conjunction policy vector
+ *
+ * @param pv A pointer to a cfe_vec struct; Represents the resulting policy vector
+ * @param dippe A pointer to a cfe_dippe struct
+ * @param num_attrib Number of attributes
+ * @param pattern Array of indices to define the policy vector
+ * @param pat_len Length of the pattern array
+ * @return Error code
+ */
+cfe_error cfe_dippe_conjunction_policy_vector_init(cfe_vec *pv, cfe_dippe *dippe, size_t num_attrib, size_t pattern[], size_t pat_len);
+
+/**
+ * cfe_dippe_cipher represents the ciphertext of the DIPPE scheme
+ */
+typedef struct cfe_dippe_cipher {
+    FP12_BN254 C_prime;
+    cfe_vec_G1 C0;
+    cfe_mat_G1 Ci;
+} cfe_dippe_cipher;
+
+/**
+ * Prepares a cipher struct
+ *
+ * @param pk A pointer to a cfe_dippe_cipher struct
+ * @param dippe A pointer to a cfe_dippe struct
+ */
+void cfe_dippe_cipher_init(cfe_dippe_cipher *cipher, cfe_dippe *dippe, size_t pol_size);
+
+/**
+ * Clears the ciphertext and frees allocated memory
+ *
+ * @param cipher A pointer to a cfe_dippe_cipher struct
+ */
+void cfe_dippe_cipher_free(cfe_dippe_cipher *cipher);
+
+/**
+ * cfe_dippe_pub_key represents the public key of the DIPPE scheme
+ */
+typedef struct cfe_dippe_pub_key {
+    ECP2_BN254 g2_sigma;
+    cfe_mat_G1 g1_W_A;
+    cfe_vec_GT gt_alpha_A;
+} cfe_dippe_pub_key;
+
+/**
+ * Prepares a public key struct
+ *
+ * @param pk A pointer to a cfe_dippe_pub_key struct
+ * @param dippe A pointer to a cfe_dippe struct
+ */
+void cfe_dippe_pub_key_init(cfe_dippe_pub_key *pk, cfe_dippe *dippe);
+
+/**
+ * Clears the public key and frees allocated memory
+ *
+ * @param pk A pointer to a cfe_dippe_pub_key struct
+ */
+void cfe_dippe_pub_key_free(cfe_dippe_pub_key *pk);
+
+/**
+ * cfe_dippe_sec_key represents the secret key of the DIPPE scheme
+ */
+typedef struct cfe_dippe_sec_key {
+    mpz_t sigma;
+    cfe_vec alpha;
+    cfe_mat W;
+} cfe_dippe_sec_key;
+
+/**
+ * Prepares a secret key struct
+ *
+ * @param pk A pointer to a cfe_dippe_sec_key struct
+ * @param dippe A pointer to a cfe_dippe struct
+ */
+void cfe_dippe_sec_key_init(cfe_dippe_sec_key *sk, cfe_dippe *dippe);
+
+/**
+ * Clears the secret key and frees allocated memory
+ *
+ * @param sk A pointer to a cfe_dippe_sec_key struct
+ */
+void cfe_dippe_sec_key_free(cfe_dippe_sec_key *sk);
+
+/**
+ * cfe_dippe_sec_key represents the user secret key of the DIPPE scheme
+ */
+typedef struct cfe_dippe_user_sec_key {
+    cfe_vec_G2 Ki;
+} cfe_dippe_user_sec_key;
+
+/**
+ * Prepares a user secret key struct
+ *
+ * @param usk A pointer to a cfe_dippe_user_sec_key struct
+ * @param dippe A pointer to a cfe_dippe struct
+ */
+void cfe_dippe_user_sec_key_init(cfe_dippe_user_sec_key *usk, cfe_dippe *dippe);
+
+/**
+ * Clears the user secret key and frees allocated memory
+ *
+ * @param usk A pointer to a cfe_dippe_user_sec_key struct
+ */
+void cfe_dippe_user_sec_key_free(cfe_dippe_user_sec_key *usk);
+
+/**
+ * Initializes an authority and generates its public and private key
+ *
+ * @param pk A pointer to a cfe_dippe_pub_key struct; Represents the public key that is about to be populated
+ * @param sk A pointer to a cfe_dippe_sec_key struct; Represents the secret key that is about to be populated
+ * @param dippe A pointer to a cfe_dippe struct
+ */
+void cfe_dippe_generate_master_keys(cfe_dippe_pub_key *pk, cfe_dippe_sec_key *sk, cfe_dippe *dippe);
+
+/**
+ * Encrypts a given message under the provided policy
+ *
+ * @param cipher A pointer to a cfe_dippe_cipher struct; Represents the ciphertext that is about to be populated
+ * @param dippe A pointer to a cfe_dippe struct
+ * @param pks An array containing references to cfe_dippe_pub_key structs;
+ * @param pks_len Length of the public key array
+ * @param pv A reference to a cfe_vec struct; Represents the policy under which the message will be encrypted
+ * @param msg A reference to a FP12_BN254 struct; Represents the message that is about to be encrypted
+ * @return Error code
+ */
+cfe_error cfe_dippe_encrypt(cfe_dippe_cipher *cipher, cfe_dippe *dippe, cfe_dippe_pub_key *pks[], size_t pks_len, cfe_vec *pv, FP12_BN254 *msg);
+
+/**
+ * Used with an authority's secret key to create a new user secret key for a given attribute vector
+ *
+ * @param usk A pointer to a cfe_dippe_user_sec_key struct; Represents the user secret key that is about to be populated
+ * @param dippe A pointer to a cfe_dippe struct
+ * @param usk_id Index of the given attribute vector for which a user secret key will be created
+ * @param pks An array containing references to cfe_dippe_pub_key structs
+ * @param pks_len Length of the public key array
+ * @param av A pointer to a cfe_vec struct; Represents the attribute vector
+ * @param gid String that represents a unique user; Required for collusion prevention
+ * @return Error code
+ */
+cfe_error cfe_dippe_keygen(cfe_dippe_user_sec_key *usk, cfe_dippe *dippe, size_t usk_id, cfe_dippe_pub_key *pks[], size_t pks_len, cfe_dippe_sec_key *sk, cfe_vec *av, char gid[]);
+
+/**
+ * Restores the underlying message of a given ciphertext
+ *
+ * @param result A pointer to a FP12_BN254 struct; Represents the resulting message
+ * @param dippe A pointer to a cfe_dippe struct
+ * @param usks An array containing cfe_dippe_user_sec_key structs; Represents the set of user secretes key used for decryption
+ * @param usks_len Length of the user secret key array
+ * @param cipher A pointer to a cfe_dippe_cipher struct; Represents the ciphertext that is about to be decrypted
+ * @param av A pointer to a cfe_vec struct; Represents the attribute vector
+ * @param gid String that represents a unique user; Required for collusion prevention
+ */
+cfe_error cfe_dippe_decrypt(FP12_BN254 *result, cfe_dippe *dippe, cfe_dippe_user_sec_key *usks, size_t usks_len, cfe_dippe_cipher *cipher, cfe_vec *av, char gid[]);
+
+#endif