arXiv subjects

Setareh Sharifian

Publications and source records attributed to Setareh Sharifian.

4 recordsLinked to original sources

arXiv2024

if-ZKP: Intel FPGA-Based Acceleration of Zero Knowledge Proofs

Zero-Knowledge Proofs (ZKPs) have emerged as an important cryptographic technique allowing one party (prover) to prove the correctness of a statement to some other party (verifier) and nothing else. ZKPs give rise to user's privacy in many applications such as blockchains, digital voting, and machine learning. Traditionally, ZKPs suffered from poor scalability but recently, a sub-class of ZKPs known as Zero-knowledge Succinct Non-interactive ARgument of Knowledges (zk-SNARKs) have addressed this challenge. They are getting significant attention and are being implemented by many public libraries. In this paper, we present a novel scalable architecture that is suitable for accelerating the zk-SNARK prover compute on FPGAs. We focus on the multi-scalar multiplication (MSM) that accounts for the majority of computation time spent in zk-SNARK systems. The MSM calculations extensive rely on modular arithmetic so highly optimized Intel IP Libraries for modular arithmetic are used. The proposed architecture exploits the parallelism inherent to MSM and is implemented using the Intel OneAPI framework for FPGAs. Our implementation runs 110x-150x faster compared to reference software library, uses a generic curve form in Jacobian coordinates and is the first to report FPGA hardware acceleration results for BLS12-381 and BN128 family of elliptic curves.

cs.AR↗

arXiv2024

CCA-Secure Hybrid Encryption in Correlated Randomness Model and KEM Combiners

A hybrid encryption (HE) system is an efficient public key encryption system for arbitrarily long messages. An HE system consists of a public key component called key encapsulation mechanism (KEM), and a symmetric key component called data encapsulation mechanism (DEM). The HE encryption algorithm uses a KEM generated key k to encapsulate the message using DEM, and send the ciphertext together with the encapsulaton of k, to the decryptor who decapsulates k and uses it to decapsulate the message using the corresponding KEM and DEM components. The KEM/DEM composition theorem proves that if KEM and DEM satisfy well-defined security notions, then HE will be secure with well defined security. We introduce HE in correlated randomness model where the encryption and decryption algorithms have samples of correlated random variables that are partially leaked to the adversary. Security of the new KEM/DEM paradigm is defined against computationally unbounded or polynomially bounded adversaries. We define iKEM and cKEM with respective information theoretic computational security, and prove a composition theorem for them and a computationally secure DEM, resulting in secure HEs with proved computational security (CPA and CCA) and without any computational assumption. We construct two iKEMs that provably satisfy the required security notions of the composition theorem. The iKEMs are used to construct two efficient quantum-resistant HEs when used with an AES based DEM. We also define and construct combiners with proved security that combine the new KEM/DEM paradigm of HE with the traditional public key based paradigm of HE.

cs.CR↗

arXiv2021

Information-theoretic Key Encapsulation and its Applications

A hybrid encryption scheme is a public-key encryption system that consists of a public-key part called the key encapsulation mechanism (KEM), and a (symmetric) secret-key part called data encapsulation mechanism (DEM): the public-key part is used to generate a shared secret key between two parties, and the symmetric key part is used to encrypt the message using the generated key. Hybrid encryption schemes are widely used for secure communication over the Internet. In this paper, we initiate the study of hybrid encryption in preprocessing model which assumes access to initial correlated variables by all parties (including the eavesdropper). We define information-theoretic KEM (iKEM) that, together with a (computationally) secure DEM, results in a hybrid encryption scheme in preprocessing model. We define the security of each building block, and prove a composition theorem that guarantees (computational) qe-chosen plaintext (CPA) security of the hybrid encryption system if the iKEM and the DEM satisfy qe-chosen encapculation attack and one-time security, respectively. We show that iKEM can be realized by a one-way SKA (OW-SKA) protocol with a revised security definition. Using an OW-SKA that satisfies this revised definition of security effectively allows the secret key that is generated by the OW-SKA to be used with a one-time symmetric key encryption system such as XORing a pseudorandom string with the message, and provide qe-CPA security for the hybrid encryption system.We discuss our results and directions for future work.

cs.CR↗

arXiv2020

A Capacity-achieving One-message Key Agreement With Finite Blocklength Analysis

Information-theoretic secret key agreement (SKA) protocols are a fundamental cryptographic primitive that are used to establish a shared secret key between two or more parties. In a two-party SKA in source model, Alice and Bob have samples of two correlated variables, that are partially leaked to Eve, and their goal is to establish a shared secret key by communicating over a reliable public channel. Eve must have no information about the established key. In this paper, we study the problem of one-message secret key agreement where the key is established by Alice sending a single message to Bob. We propose a one-message SKA (OM-SKA) protocol, prove that it achieves the one-way secret key capacity, and derive finite blocklength approximations of the achievable secret key length. We compare our results with existing OM-SKAs and show the protocol has a unique combination of desirable properties.

cs.CR↗