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In this paper, we propose a lattice-based encryption scheme for Identity-Based Encryption (IBE) which is secure against Chosen-Ciphertext Attacks (CCA), and it is deduced from a previous Chosen-Plaintext Attack (CPA) secure IBE scheme by applying Fujisaki-Okamoto transform. Also, we present the design of a lattice-based cryptoprocessor that performs the encryption or decryption of the proposed CCA IBE scheme for the security parameters $n=512$ and $n=1024$ . In this case, the cryptoprocessor is mainly composed of one Random Number Generator (RNG), two hash function cores based on the Secure Hash Algorithm-3 (SHA-3) standard, and one Number Theoretical Transform (NTT) core for performing the polynomial ring operations. NTT core is designed using a systolic array and radix-2 multiple-path delay commutator architecture. The cryptoprocessor was synthesized on FPGA EP4SGX230KF40C2 using Quartus Prime 17.1, and verified in hardware using DE4 board and SignalTap tool. According to the obtained synthesis results, for the security parameter $n =1024$ , the IBE cryptoprocessor performs the encryption in $21.10~\mu $ s, and the decryption in $24.87~\mu $ s.

Injected false reports by attackers bring fateful consequences in wireless sensor networks, i.e., wasting the limited batteries of nodes and misleading the decision making of users. Existing security designs mainly attach some extra fields by a group of sensing nodes after the pure data, and check the correctness of attached MACs (Message Authentication Codes) in the process of report forwarding, each of which represents the agreement of sensors on the report, thus to drop the ones which failed on MAC checking. They cannot recognize the reports forged by t arbitrary compromised sensors collaboratively; the variable t is a security parameter. Furthermore, failures of reporting usually occur in sparse regions for lacking of enough detecting sensors, which is incurred by the complicated deploying region and the adopted random deploying strategy. This paper proposes a Location and Optimal Coverage based Filtering scheme (LOCF). It first derived the optimal coverage degree Δ by considering both the network size and covering efficiency, and then employed covering algorithm to deploy sensors accordingly. Each deployed sensor has to dispense its location to downstream sensors, through which sensors are bounded with locations. A report for the observed event must attach t endorsements along with locations of detecting sensors. In the forwarding process, intermediate sensors evaluate the correctness and rationality of both MACs and locations. Simulation results demonstrate that LOCF outperforms existing works in terms of covering effectiveness, filtering efficiency and compromise robustness.

In this paper, a novel privacy-preserving signature scheme for network coding is proposed, which can mitigate both intra-generation and inter-generation pollution attacks efficiently, and leverage the inherent security property of random network coding to prevent eavesdropping attacks at the same time. Our scheme is constructed on a bi-linear map between two multiplicative cyclic groups with the same order, and its security relies on the hardness of the discrete logarithm problem. We proved that the construction of our scheme is correct, and also showed that our scheme is resistant against both pollution attacks and eavesdropping attacks by demonstrating that the probabilities of an adversary recovering the native messages and forging a valid signature for a bogus packet are both negligible functions of the security parameter. We evaluated the performance of our scheme in terms of communication overhead and computational complexity, and carried out extensive experiments to compare the running time of different procedures between our scheme and several previous schemes. The experimental results showed that our scheme is more efficient than the previous schemes simulated.

Recently, Mao, Zhang, Wu et al. constructed two key exchange (KE) protocols based on tensor ergodic problem (TEP). Although they conjectured that these constructions can potentially resist quantum computing attack, they did not provide a rigorous security proof for their KE protocols. In this paper, applying the properties of ergodic matrix, we first present a polynomial time algorithm to solve the TEP problem using O(n6) arithmetic operations in the finite field, where n is the security parameter. Then, applying this polynomial time algorithm, we generate a common shared key for two TEP-based KE constructions, respectively. In addition, we also provide a polynomial time algorithm with O(n6) arithmetic operations that directly recovers the plaintext from a ciphertext for the KE-based encryption scheme. Thus, the TEP-based KE protocols and their corresponding encryption schemes are insecure.

We study linear complementary pairs (LCP) of codes $(C, D)$ , where both codes belong to the same algebraic code family. We especially investigate constacyclic and quasi-cyclic LCP of codes. We obtain characterizations for LCP of constacyclic codes and LCP of quasi-cyclic codes. Our result for the constacyclic complementary pairs extends the characterization of linear complementary dual (LCD) cyclic codes given by Yang and Massey. We observe that when $C$ and $D$ are complementary and constacyclic, the codes $C$ and $D^\bot $ are equivalent to each other. Hence, the security parameter $\min (d(C),d(D^\bot))$ for LCP of codes is simply determined by one of the codes in this case. The same holds for a special class of quasi-cyclic codes, namely 2D cyclic codes, but not in general for all quasi-cyclic codes, since we have examples of LCP of double circulant codes not satisfying this conclusion for the security parameter. We present examples of binary LCP of quasi-cyclic codes and obtain several codes with better parameters than known binary LCD codes. Finally, a linear programming bound is obtained for binary LCP of codes and a table of values from this bound is presented in the case $d(C)=d(D^\bot)$ . This extends the linear programming bound for LCD codes.

The security parameter for a linear complementary pair $(C,D)$ of codes is defined to be the minimum of the minimum distances $d(C)$ and $d(D^\bot)$ . Recently, Carlet et al. showed that if $C$ and $D$ are both cyclic or both 2-D cyclic linear complementary pair of codes, and then, $C$ and $D^\bot$ are equivalent codes. Hence, the security parameter for cyclic and 2-D cyclic linear complementary pair of codes is simply $d(C)$ . We extend this result to $n\text{D}$ cyclic linear complementary pair of codes. The proof of Carlet et al. for the 2-D cyclic case is based on the trace representation of the codes, which is technical and nontrivial to generalize. Our proof for the generalization is based on the zero sets of the ideals corresponding to $n\text{D}$ cyclic codes.

We present a fuzzy extractor whose security can be reduced to the hardness of Learning Parity with Noise (LPN) and can efficiently correct a constant fraction of errors in a biometric source with a “noise-avoiding trapdoor.” Using this computational fuzzy extractor, we present a stateless construction of a cryptographically-secure Physical Unclonable Function. Our construct requires no non-volatile (permanent) storage, secure or otherwise, and its computational security can be reduced to the hardness of an LPN variant under the random oracle model. The construction is “stateless,” because there is no information stored between subsequent queries, which mitigates attacks against the PUF via tampering. Moreover, our stateless construction corresponds to a PUF whose outputs are free of noise because of internal error-correcting capability, which enables a host of applications beyond authentication. We describe the construction, provide a proof of computational security, analysis of the security parameter for system parameter choices, and present experimental evidence that the construction is practical and reliable under a wide environmental range.

Recently, homomorphic message authentication code (MAC) schemes have been proposed to resist against pollution attacks in network coding. However, existing methods face a common challenge: the generated MAC t belongs to a small finite field Fq, which means that an adversary could attack by randomly guessing the value of t, and succeed with probability 1/q. Since q is a predetermined system parameter which is typically set as 28, the resulted security 1/256 could be unsatisfactory in practice. In this paper, we propose an efficient homomorphic MAC for authentication in network coding. The proposed method achieves a reliable security parameter 1/ql using only one key, where l could be chosen according to different security requirements. Compared with previous approaches that using multiple tags, the proposed homomorphic MAC has both low computation and communication overheads.

We present a new mechanized prover for secrecy properties of cryptographic protocols. In contrast to most previous provers, our tool does not rely on the Dolev-Yao model, but on the computational model. It produces proofs presented as sequences of games; these games are formalized in a probabilistic polynomial-time process calculus. Our tool provides a generic method for specifying security properties of the cryptographic primitives, which can handle shared-and public-key encryption, signatures, message authentication codes, and hash functions. Our tool produces proofs valid for a number of sessions polynomial in the security parameter, in the presence of an active adversary. We have implemented our tool and tested it on a number of examples of protocols from the literature.

In this paper, we investigate the decoding problem of Reed-Solomon (RS) codes, also known as the polynomial reconstruction problem (PR), from a cryptographic hardness perspective. Namely, we deal with samplable PR instances over parameter choices for which decoding is not known to be feasibly solvable and where part of the solution polynomial is the hidden input. We put forth a natural decisional intractability assumption that relates to this decoding problem: distinguishing between a single randomly chosen error location and a single randomly chosen nonerror location for a given corrupted RS codeword with random noise. We prove that under this assumption, PR instances are entirely pseudorandom, i.e., they are indistinguishable from random vectors over the underlying finite field. Moreover, under the same assumption, we show that it is hard to extract any partial information related to the hidden input encoded by the corrupted PR instance, i.e., PR instances hide their message polynomial solution in the semantic security sense. The above results lay a framework for the exploitation of PR as an intractability assumption for provable security of cryptographic primitives. Based on this framework, we present provably secure cryptographic constructions for (1) a pseudorandom number generator, (2) a semantically secure version of the oblivious polynomial evaluation (OPE) protocol, and (3) a stateful cipher with a set of interesting properties that include: semantic security, forward secrecy, error-correcting decryption and an array of random self-reducibility properties with respect to the plaintext choice, key choice, and partial domain choice.

Recently, an efficient homomorphic MAC scheme for authentication in network coding is proposed and it is claimed that it achieves a security parameter $1/q^l$ where $l$ is selected according to different security requirements. However, in this paper, we show that there is an attack to make the security parameter $1/q$ instead of $1/q^l$ . And we propose a way to avoid the presented attack.

We address the problem of the-security of cryptographic protocols in face of future advances in computing technology and algorithmic research. The problem stems from the fact may be deemed that computations which at a given point in time may be deemed infeasible, can, in the course of years or decades, be made possible with improved hardware and/or breakthroughs in code-breaking algorithms. In such cases, the security of historical , but nonetheless highly confidential data may be in jeopardy. We present a scheme for efficient secure two-party communication with provable everlasting security. The security is guaranteed in face of any future technological advances, given the current state of of the art. Furthermore, the security of the messages is also guaranteed even if the secret encryption/decryption key is revealed in the future, The scheme is based on the bounded storage model and provides information-theoretic security in this model. The bounded storage model postulates an adversary who is computationally unbounded, and is only bounded in the amount of storage (not computation space) available to store the output of his computation. The bound on the storage can be arbitrarily large (e.g., 100 Tbytes), as long as it is fixed. Given this storage bound, our protocols guarantee that even a computationally all powerful adversary gains no information about a message (except with a probability that is exponentially small in the security parameter k). The bound on storage space need only hold at the time of the message transmission. Thereafter, no additional storage space or, computational power can help the adversary in deciphering the message. We present two protocols. The first protocol, which elaborates on the autoregressive (AR) protocol of Aumann and Rabin (see Advances in Cryptology-Crypto '99, p. 65-79, 1999), employs a short secret key whose size is independent of the length of the message, but uses many public random bits. The second protocol uses an optimal number of public random bits, but employs a longer secret key. Our proof of security utilizes a novel linear algebraic technique.

Recently, homomorphic message authentication code (MAC) schemes have been proposed to thwart pollution attacks in network coding. However, existing schemes adopt the inner product operation to construct the MAC, which could be broken with probability Pr=1/q, where the predetermined system parameter q is typically set as 28. Usually, the homomorphic MAC with a security parameter Pr=1/28 may not be sufficient in practice. In this letter, we propose a novel scheme and its key idea is to employ the trace function over a finite field to construct the homomorphic MAC. The proposed method could achieve a reliable security Pr=1/ql without increasing the field size or employing multiple keys, where l is a positive integer greater than or equal to 1.