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cryptography
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Post-quantum cryptoprocessors optimized for edge and resource-constrained devices in IoT
, Article IEEE Internet of Things Journal ; Volume 6, Issue 3 , 2019 , Pages 5500-5507 ; 23274662 (ISSN) ; Bayat Sarmadi, S ; Mosanaei Boorani, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
By exponential increase in applications of the Internet of Things (IoT), such as smart ecosystems or e-health, more security threats have been introduced. In order to resist known attacks for IoT networks, multiple security protocols must be established among nodes. Thus, IoT devices are required to execute various cryptographic operations, such as public key encryption/decryption. However, classic public key cryptosystems, such as Rivest-Shammir-Adlemon and elliptic curve cryptography are computationally more complex to be efficiently implemented on IoT devices and are vulnerable regarding quantum attacks. Therefore, after complete development of quantum computing, these cryptosystems will...
Reducing the key length of mceliece cryptosystem using polar codes
, Article 2014 11th International ISC Conference on Information Security and Cryptology, ISCISC 2014 ; Sept , 2014 , pp. 104-108 ; ISBN: 9781479953837 ; Koochak Shooshtari, M ; Eghlidos, T ; Aref, M. R ; Sharif University of Technology
Abstract
This paper introduces a public key scheme based on polar codes to improve the performance of McEliece cryptosystem. By exploiting the interesting properties of polar codes, we put the encryption matrix of the proposed scheme in systematic form. Moreover, the nonsingular matrix is constructed from the generator matrix of used polar code. These proceedings lead to decrease the public and private key lengths compared with the original McEliece public key cryptosystem. We analyze the proposed scheme against known attacks on the public key cryptosystems based on channel coding. Moreover, it benefits from high code rate and proper error correction capability for reliable communication
A lattice-based threshold secret sharing scheme
, Article 2014 11th International ISC Conference on Information Security and Cryptology, ISCISC 2014 ; Sept , 2014 , pp. 173-179 ; ISBN: 9781479953837 ; Asaad, S ; Eghlidos, T ; Aref, M ; Sharif University of Technology
Abstract
In this paper, we introduce a method of threshold secret sharing scheme in which secret reconstruction is based on celebrated Babai lattice algorithm. In order to supply secure public channels for transmitting shares to parties, we need to ensure that there is no quantum threats to these channels. One solution for this problem can be utilization of lattice cryptosystems for these channels which requires designing lattice based secret sharing schemes. We indicate that our scheme is asymptotically correct. Moreover, we analyze the security of our scheme by giving a quantitative proof of security from the view point of information theory
Identity-based universal re-encryption for mixnets
, Article Security and Communication Networks ; Volume 8, Issue 17 , February , 2015 , Pages 2992-3001 ; 19390114 (ISSN) ; Mohajeri, J ; Salmasizadeh, M ; Sharif University of Technology
John Wiley and Sons Inc
2015
Abstract
In order to provide anonymity, universal cryptosystems have been used in various applications, including mixnets with multiple receivers. Unlike ordinary re-encryption cryptosystems, universal cryptosystems for re-encryption of ciphertexts do not require knowledge of the public key of the receiver. Golle et al. introduced universal cryptosystems for public key cryptography. Contrary to public key cryptography, in ID-based cryptography, a public key infrastructure is not needed, which makes it suitable for situations where it is not cost-effective to distribute certificates or establish a public key infrastructure. In this paper, we first generalize the definition of universal cryptosystems...
Biclique cryptanalysis of Twine-128
, Article 13th International ISC Conference on Information Security and Cryptology, 7 September 2016 through 8 September 2016 ; 2016 , Pages 46-51 ; 9781509039494 (ISBN) ; Zare Ahangarkolaei, M ; Ahmadi, S ; Aref, M. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
Abstract
Security evaluation of lightweight block ciphers plays a critical role to determine security margin of these ciphers. One of the methods to find the security margin of block ciphers is biclique cryptanalysis. In this paper, we present a new schematic for biclique attack which combines asymmetric biclique and early abort technique. Then, we apply it against Twine-128 to evaluate the security margin of Twine-128. As a result, we present two cryptanalysis for Twine-128, one with 2125.75 computational complexity and 260 data complexity, and the other with 212616 computational complexity and 28 data complexity. To the best of our knowledge, our results are the best in computational and data...
Fully distributed ECC-based key management for mobile ad hoc networks
, Article Computer Networks ; Volume 113 , 2017 , Pages 269-283 ; 13891286 (ISSN) ; Moradlou, Z ; Doostari, M. A ; Movaghar, A ; Sharif University of Technology
Elsevier B.V
2017
Abstract
Dynamic nature of mobile ad hoc networks combined with their lack of centralized infrastructure make security problem the most challenging issue in such networks. The main contribution of this paper is to propose a secure and efficient key management algorithm, able to satisfying the requirement of such networks and facing their specific characteristics. The proposed algorithm is a fully distributed ID-based system which is built based on elliptic curve cryptography. The main advantage of the proposed algorithm, that gives it the superiority in its field of research, is the improvement of the performance and the security strength together. The proposed algorithm is implemented with much...
An efficient low-latency point-multiplication over curve25519
, Article IEEE Transactions on Circuits and Systems I: Regular Papers ; Volume 66, Issue 10 , 2019 , Pages 3854-3862 ; 15498328 (ISSN) ; Bayat Sarmadi, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
The elliptic curve cryptography (ECC) has gained attention mainly due to its lower complexity compared to other asymmetric methods while providing the same security level. The most performance critical operation in ECC is the point multiplication. Thus, its efficient implementation is desirable. One of the most secure and lightweight ECC curves, which satisfies all standard security criteria, is the Curve25519. In this paper, a low latency Karatsuba-Ofman-based field multiplier (KOM) and an efficient point multiplication over Curve25519 have been proposed. The improvements have been achieved mainly due to the proposed low latency pipelined KOM and efficient scheduling of field operations....
An identity-based online/offline secure cloud storage auditing scheme
, Article Cluster Computing ; Volume 23, Issue 2 , 2020 , Pages 1455-1468 ; Rajabzadeh Asaar, M ; Ahmadian Attari, M ; Aref, M. R ; Sharif University of Technology
Springer
2020
Abstract
Cloud storage has significantly reduced data management costs for data owners. However, loss of physical control over the data after outsourcing, triggers some security concerns such as data integrity. Provable Data Possession (PDP) protocols, enable data owners to audit the integrity of their outsourced data without the need to retrieve the file from cloud server. However, most existing PDP schemes require resource-constrained users to perform costly operations for generating metadata on file blocks. In online/offline PDP mechanisms introduced most recently, the user’s computation is divided into online/offline phases, where the costly operations are allowed to be carried out in the offline...
Smooth projective hash function from codes and its applications
, Article IEEE Transactions on Services Computing ; 2021 ; 19391374 (ISSN) ; Aref, M. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Nowadays, Smooth Projective Hash Functions (SPHFs) play an important role in constructing cryptographic tools such as secure Password-based Authenticated Key Exchange (PAKE) protocol in the standard model, oblivious transfer, and zero-knowledge proofs. Specifically, in this paper, we focus on constructing PAKE protocol; that is, a kind of key exchange protocol which needs only a low entropy password to produce a cryptographically strong shared session key. In spite of relatively good progress of SPHFs in applications, it seems there has been little effort to build them upon quantum-resistant assumptions such as lattice-based cryptography and code-based cryptography to make them secure...
Generalization of Auxiliary Input Leakage Model for Public-Key Cryptosystems
, M.Sc. Thesis Sharif University of Technology ; Khazaei, Shahram (Supervisor)
Abstract
Side channel attacks, where an attacker learns some physical information about the state of a device, are one of the ways in which cryptographic schemes are broken in practice. leakage resilient ryptography addressed this issue at a higher abstraction level, proposing models capturing such attacks. Auxiliary Input is one of these models. In this thesis, we study public-key encryption schemes in this model of leakage. we also propose a method to consider this leakage continuously (i.e., not just one observation of the adversary). at the end, we consider the leakage from both the secret key owner and the encryptor. This odel captures a wider class of side-channel attacks
A Lattice based Threshold Multi-Secret Sharing Scheme and its Application to Threshold Cryptography
, Ph.D. Dissertation Sharif University of Technology ; Eghlidos, Taraneh (Supervisor)
Abstract
Secret sharing schemes are used for storage and management of sensitive data such as cryptographic keys and bank account numbers. These schemes provide both confidentiality and reliability. Advances in quantum computers have threatened the security of currently used public-key cryptographic algorithms. In this thesis, for designing quantum resistant cryptographic schemes, we construct a lattice based threshold multi-stage secret sharing (TMSSS) scheme. Using a lattice based one-way function, even after some secrets are revealed, the computational security of the unrecovered secrets is provided against quantum computers. The scheme is multi-use and verifiable meaning that the participants can...
GPU-based Acceleration of Isogeny-based Cryptography
, M.Sc. Thesis Sharif University of Technology ; Bayat Sarmadi, Siavash (Supervisor)
Abstract
Post-quantum cryptography, as one of the newest groups of cryptographic algorithms, is thought to be secure against most sophisticated attacks by the groundbreaking quantum computers. Isogeny-based cryptography is an appealing contender among them due to its exceptional characteristics, especially the shortest public key in key encapsulation, encryption and decryption amid the other nominees of NIST post-quantum standard. However, its high computational complexity is a significant drawback. This research aims to increase the performance of isogeny-based cryptography in the most compute-intensive part, both in throughput and latency perspectives on GPUs and CPUs, which are the most widespread...
A novel probabilistic key management algorithm for large-scale MANETs
, Article Proceedings - 27th International Conference on Advanced Information Networking and Applications Workshops ; 2013 , Pages 349-356 ; 9780769549521 (ISBN) ; Emamjomeh Zadeh, E ; Norouzi Fard, A ; Movaghar, A ; Sharif University of Technology
2013
Abstract
Mobile ad hoc networks (MANETs) have become very interesting during last years, but the security is the most important problem they suffer from. Asymmetric cryptography is a very useful solution to provide a secure environment in multihop networks where intermediate nodes are able to read, drop or change messages before resending them. However, storing all keys in every node by this approach is inefficient, if practically possible, in large-scale MANETs due to some limitations such as memory or process capability. In this paper, we propose a new probabilistic key management algorithm for large-scale MANETs. To the best of our knowledge, this is the first method which probabilistically uses...
Secret key cryptosystem based on polar codes over Binary Erasure Channel
, Article 2013 10th International ISC Conference on Information Security and Cryptology, ISCISC 2013 ; 2013 ; Shooshtari, M. K ; Aref, M. R ; Sharif University of Technology
2013
Abstract
This paper proposes an efficient secret key cryptosystem based on polar codes over Binary Erasure Channel. We introduce a method, for the first time to our knowledge, to hide the generator matrix of the polar codes from an attacker. In fact, our main goal is to achieve secure and reliable communication using finite-length polar codes. The proposed cryptosystem has a significant security advantage against chosen plaintext attacks in comparison with the Rao-Nam cryptosystem. Also, the key length is decreased after applying a new compression algorithm. Moreover, this scheme benefits from high code rate and proper error performance for reliable communication
Identity based universal re-encryption for mix nets
, Article 2013 10th International ISC Conference on Information Security and Cryptology, ISCISC 2013 ; Aug , 2013 , 1 - 5 ; Mohajeri, J ; Salmasizadeh, M ; Sharif University of Technology
IEEE Computer Society
2013
Abstract
Universal Re-encryption Cryptosystems do not require the knowledge of the recipient's public key for re-encrypting a ciphertext whereas conventional Re-encryption Cryptosystems need that knowledge. In this paper, we present the first Identity-based Universal Re-encryption Cryptosystem scheme whose re-encryption algorithm does not need to have the knowledge of the recipient's identity. By generalizing the definition of Universal Semantic Security to Identity Based Universal Cryptosystems, we prove the security of our scheme. There are some applications for universal re-encryption cryptosystems which cannot be made using conventional cryptosystems. One significant application of these...
Physical layer encryption scheme using finite-length polar codes
, Article IET Communications ; Volume 9, Issue 15 , 2015 , Pages 1857-1866 ; 17518628 (ISSN) ; Aref, M. R ; Eghlidos, T ; Sharif University of Technology
Institution of Engineering and Technology
2015
Abstract
In this study, by exploiting the properties of finite-length polar codes, the authors introduce a physical layer encryption scheme to make secure (from a computational security perspective) and efficient communication between a sender (Alice) and a legitimate receiver (Bob) against both active and passive attacks, simultaneously. To prevent active attacks, two techniques are considered: (i) a novel method is introduced to keep the generator matrix of polar code secret from an active attacker (Oscar); (ii) a proper joint polar encoding/encryption algorithm based on the hidden generator matrix is introduced. Two additional strategies are considered against passive attacks: (i) a new method is...
A lightweight identity-based provable data possession supporting users’ identity privacy and traceability
, Article Journal of Information Security and Applications ; Volume 51 , 2020 ; Ahmadian Attari, M ; Rajabzadeh Asaar, M ; Aref, M. R ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Cloud storage auditing is considered as a significant service used to verify the integrity of data stored in public cloud. However, most existing auditing protocols suffer form complex certificate management/verification since they rely on expensive Public Key Infrastructure (PKI). On the other hand, most cloud users have constrained computational resources. The few existing ID-based storage auditing protocols in the literature, require resource-constrained users to perform costly operations for generating metadata on file blocks. In this paper, we propose a storage auditing protocol which benefits from ID-based structure and lightweight user computations, simultaneously. Our construction...
Improved user identity confidentiality for UMTS mobile networks
, Article ECUMN 2007: Fourth European Conference on Universal Multiservice Networks, Toulouse, 14 February 2007 through 16 February 2007 ; 2007 , Pages 401-409 ; 076952768X (ISBN); 9780769527680 (ISBN) ; Asadpour, M ; Jalili, R ; Sharif University of Technology
2007
Abstract
In UMTS mobile networks, there are some circumstances that the International Mobile Subscriber Identity (IMSI) of a user is conveyed in clear-text over the radio interface. Such situations violate the anonymity of users. In this paper, we introduce an Improved User Identity Confidentiality (IUIC) mechanism which attempts to avoid the drawback and makes users more anonymous. We give the role of IMSI to anonymous tickets in such a way that IMSI is never exposed on the radio interface or over any other link. Our IUIC mechanism, employs symmetric cryptography based on the existing network access security features of UMTS. Its implementation, security, and performance issues are also considered....
A novel video watermarking method using visual cryptography
, Article IEEE International Conference on Engineering of Intelligent Systems, ICEIS 2006, Islamabad, 22 April 2006 through 23 April 2006 ; 2006 ; 1424404568 (ISBN); 9781424404568 (ISBN) ; Ghaemmaghami, S ; Sharif University of Technology
2006
Abstract
In this paper we propose a novel approach to insertion of watermark in the video sequences. The proposed scheme is based on visual cryptography and performs temporal scrambling for watermark embedding. Watermark, which may be a visible logo, is frequently split and inserted into video frames. Watermark detection can be verified by the human eye. Inserted watermark is expected to resist collusion attack, which is a major concern in video watermarking. Experimental results show that the proposed method provides a high resilience against some non-hostile video processing schemes, such as geometrical distortions. © 2006 IEEE
Improving data protection in BSS based secure communication: mixing matrix design
, Article Wireless Networks ; Volume 27, Issue 7 , 2021 , Pages 4747-4758 ; 10220038 (ISSN) ; Shamsollahi, M. B ; Nouri, A ; Sharif University of Technology
Springer
2021
Abstract
Abstract: In this paper, a secure and efficient Blind Source Separation (BSS) based cryptosystem is presented. The use of BSS in audio and image cryptography in wireless networks has attracted more attention. A BSS based cryptosystem consists of three main parts: secret data, secret keys, and mixing matrix. In this paper, we propose a new design to create a proper mixing matrix in BSS based cryptosystem. We offer a mathematical criterion to select mixing matrix elements before encryption. The proposed criterion gives a simple way to attach the secret sources to keys, which makes source separation very hard for the adversary. Versus, we show that using the random mixing matrix can lead to...