Cryptography

1124 KiB

Open AccessArticle

Cryptanalysis and Improvement of ECC Based Authentication and Key Exchanging Protocols

by Swapnoneel Roy and Chanchal Khatwani

Cryptography 2017, 1(1), 9; https://doi.org/10.3390/cryptography1010009 - 13 Jun 2017

Cited by 23 | Viewed by 14353

Elliptic curve cryptography (ECC) is extensively used in various multifactor authentication protocols. In this work, various recent ECC-based authentication and key exchange protocols are subjected to threat modeling and static analysis to detect vulnerabilities and to enhance them to be more secure against [...] Read more.

Elliptic curve cryptography (ECC) is extensively used in various multifactor authentication protocols. In this work, various recent ECC-based authentication and key exchange protocols are subjected to threat modeling and static analysis to detect vulnerabilities and to enhance them to be more secure against threats. This work demonstrates how currently-used ECC-based protocols are vulnerable to attacks. If protocols are vulnerable, damage could include critical data loss and elevated privacy concerns. The protocols considered in this work differ in their usage of security factors (e.g., passwords, pins and biometrics), encryption and timestamps. The threat model considers various kinds of attacks including denial of service, man in the middle, weak authentication and SQL injection. Countermeasures to reduce or prevent such attacks are suggested. Beyond cryptanalysis of current schemes and the proposal of new schemes, the proposed adversary model and criteria set forth provide a benchmark for the systematic evaluation of future two-factor authentication proposals. Full article

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4926 KiB

Open AccessFeature PaperArticle

Analysis of Entropy in a Hardware-Embedded Delay PUF

by Wenjie Che, Venkata K. Kajuluri, Mitchell Martin, Fareena Saqib and Jim Plusquellic

Cryptography 2017, 1(1), 8; https://doi.org/10.3390/cryptography1010008 - 7 Jun 2017

Cited by 20 | Viewed by 11026

Abstract

The magnitude of the information content associated with a particular implementation of a Physical Unclonable Function (PUF) is critically important for security and trust in emerging Internet of Things (IoT) applications. Authentication, in particular, requires the PUF to produce a very large number [...] Read more.

The magnitude of the information content associated with a particular implementation of a Physical Unclonable Function (PUF) is critically important for security and trust in emerging Internet of Things (IoT) applications. Authentication, in particular, requires the PUF to produce a very large number of challenge-response-pairs (CRPs) and, of even greater importance, requires the PUF to be resistant to adversarial attacks that attempt to model and clone the PUF (model-building attacks). Entropy is critically important to the model-building resistance of the PUF. A variety of metrics have been proposed for reporting Entropy, each measuring the randomness of information embedded within PUF-generated bitstrings. In this paper, we report the Entropy, MinEntropy, conditional MinEntropy, Interchip hamming distance and National Institute of Standards and Technology (NIST) statistical test results using bitstrings generated by a Hardware-Embedded Delay PUF called HELP. The bitstrings are generated from data collected in hardware experiments on 500 copies of HELP implemented on a set of Xilinx Zynq 7020 SoC Field Programmable Gate Arrays (FPGAs) subjected to industrial-level temperature and voltage conditions. Special test cases are constructed which purposely create worst case correlations for bitstring generation. Our results show that the processes proposed within HELP to generate bitstrings add significantly to their Entropy, and show that classical re-use of PUF components, e.g., path delays, does not result in large Entropy losses commonly reported for other PUF architectures. Full article

(This article belongs to the Special Issue PUF-Based Authentication)

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219 KiB

Open AccessArticle

Maximum-Order Complexity and Correlation Measures

by Leyla Işık and Arne Winterhof

Cryptography 2017, 1(1), 7; https://doi.org/10.3390/cryptography1010007 - 13 May 2017

Cited by 10 | Viewed by 8793

Abstract

We estimate the maximum-order complexity of a binary sequence in terms of its correlation measures. Roughly speaking, we show that any sequence with small correlation measure up to a sufficiently large order k cannot have very small maximum-order complexity. Full article

1650 KiB

Open AccessArticle

Garbled Quantum Computation

by Elham Kashefi and Petros Wallden

Cryptography 2017, 1(1), 6; https://doi.org/10.3390/cryptography1010006 - 7 Apr 2017

Cited by 11 | Viewed by 9672

Abstract

The universal blind quantum computation protocol (UBQC) enables an almost classical client to delegate a quantum computation to an untrusted quantum server (in the form of a garbled quantum circuit) while the security for the client is unconditional. In this contribution, we explore [...] Read more.

The universal blind quantum computation protocol (UBQC) enables an almost classical client to delegate a quantum computation to an untrusted quantum server (in the form of a garbled quantum circuit) while the security for the client is unconditional. In this contribution, we explore the possibility of extending the verifiable UBQC, to achieve further functionalities following the analogous research for classical circuits (Yao 1986). First, exploring the asymmetric nature of UBQC (the client preparing only single qubits, while the server runs the entire quantum computation), we present a “Yao”-type protocol for secure two-party quantum computation. Similar to the classical setting, our quantum Yao protocol is secure against a specious (quantum honest-but-curious) garbler, but in our case, against a (fully) malicious evaluator. Unlike the previous work on quantum two-party computation of Dupuis et al., 2010, we do not require any online-quantum communication between the garbler and the evaluator and, thus, no extra cryptographic primitive. This feature will allow us to construct a simple universal one-time compiler for any quantum computation using one-time memory, in a similar way to the classical work of Goldwasser et al., 2008, while more efficiently than the previous work of Broadbent et al., 2013. Full article

(This article belongs to the Special Issue Quantum-Safe Cryptography)

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145 KiB

Open AccessBook Review

Privacy in a Digital, Networked World: Technologies, Implications and Solutions. By Sherali Zeadally and Mohamad Badra. Springer International Publishing: 418 pp.; $51.89; ISBN-10: 3319084690, ISBN-13: 978-3319084695

by Nicolas Sklavos

Cryptography 2017, 1(1), 5; https://doi.org/10.3390/cryptography1010005 - 19 Mar 2017

Viewed by 8050

Abstract

The book entitled Privacy in a Digital, Networked World: Technologies, Implications and Solutions of the series Computer Communications and Networks is the latest published book edited by Sherali Zeadally and Mohamad Badra.[...] Full article

928 KiB

Open AccessReview

Cryptography in Wireless Multimedia Sensor Networks: A Survey and Research Directions

by Daniel G. Costa, Solenir Figuerêdo and Gledson Oliveira

Cryptography 2017, 1(1), 4; https://doi.org/10.3390/cryptography1010004 - 5 Jan 2017

Cited by 44 | Viewed by 14708

Abstract

Wireless multimedia sensor networks will play a central role in the Internet of Things world, providing content-rich information for an uncountable number of monitoring and control scenarios. As more applications rely on multimedia data, security concerns gain attention, and new approaches arise to [...] Read more.

Wireless multimedia sensor networks will play a central role in the Internet of Things world, providing content-rich information for an uncountable number of monitoring and control scenarios. As more applications rely on multimedia data, security concerns gain attention, and new approaches arise to provide security for such networks. However, the usual resource constraints of processing, memory and the energy of multimedia-based sensors have brought different challenges for data encryption, which have driven the development of different security approaches. In this context, this article presents the state-of-the-art of cryptography in wireless multimedia sensor networks, surveying innovative works in this area and discussing promising research directions. Full article

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3758 KiB

Open AccessArticle

A Privacy-Preserving, Mutual PUF-Based Authentication Protocol

by Wenjie Che, Mitchell Martin, Goutham Pocklassery, Venkata K. Kajuluri, Fareena Saqib and Jim Plusquellic

Cryptography 2017, 1(1), 3; https://doi.org/10.3390/cryptography1010003 - 25 Nov 2016

Cited by 49 | Viewed by 12227

Abstract

This paper describes an authentication protocol using a Hardware-Embedded Delay PUF called HELP. HELP derives randomness from within-die path delay variations that occur along the paths within a hardware implementation of a cryptographic primitive, such as AES or SHA-3. The digitized timing values [...] Read more.

This paper describes an authentication protocol using a Hardware-Embedded Delay PUF called HELP. HELP derives randomness from within-die path delay variations that occur along the paths within a hardware implementation of a cryptographic primitive, such as AES or SHA-3. The digitized timing values which represent the path delays are stored in a database on a secure server (verifier) as an alternative to storing PUF response bitstrings. This enables the development of an efficient authentication protocol that provides both privacy and mutual authentication. The security properties of the protocol are analyzed using data collected from a set of Xilinx Zynq FPGAs. Full article

(This article belongs to the Special Issue Physical Security in a Cryptographic Enviroment)

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422 KiB

Open AccessArticle

Balanced Permutations Even–Mansour Ciphers

by Shoni Gilboa, Shay Gueron and Mridul Nandi

Cryptography 2017, 1(1), 2; https://doi.org/10.3390/cryptography1010002 - 1 Apr 2016

Cited by 3 | Viewed by 9398

Abstract

The r-rounds Even–Mansour block cipher is a generalization of the well known Even–Mansour block cipher to r iterations. Attacks on this construction were described by Nikolić et al. and Dinur et al. for

r = 2, 3

. These attacks are [...] Read more.

The r-rounds Even–Mansour block cipher is a generalization of the well known Even–Mansour block cipher to r iterations. Attacks on this construction were described by Nikolić et al. and Dinur et al. for

r = 2, 3

. These attacks are only marginally better than brute force but are based on an interesting observation (due to Nikolić et al.): for a “typical” permutation P, the distribution of

P (x) \oplus x

is not uniform. This naturally raises the following question. Let us call permutations for which the distribution of

P (x) \oplus x

is uniformly “balanced” — is there a sufficiently large family of balanced permutations, and what is the security of the resulting Even–Mansour block cipher? We show how to generate families of balanced permutations from the Luby–Rackoff construction and use them to define a

2 n

-bit block cipher from the 2-round Even–Mansour scheme. We prove that this cipher is indistinguishable from a random permutation of

{0, 1}^{2 n}

, for any adversary who has oracle access to the public permutations and to an encryption/decryption oracle, as long as the number of queries is

o (2^{n / 2})

. As a practical example, we discuss the properties and the performance of a 256-bit block cipher that is based on our construction, and uses the Advanced Encryption Standard (AES), with a fixed key, as the public permutation. Full article

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268 KiB

Open AccessEditorial

Cryptography: A New Open Access Journal

by Kwangjo Kim

Cryptography 2017, 1(1), 1; https://doi.org/10.3390/cryptography1010001 - 15 Feb 2016

Cited by 2 | Viewed by 10632

Abstract

Cryptography has very long history, from ancient ciphers, such as Ceaser cipher, machine (or rotor) cipherx during WWI and WWII, and modern ciphers, which play a fundamental role in providing Confidentiality, Integrity, and Authentication services during transmission, processing, and storage of the sensitive [...] Read more.

Cryptography has very long history, from ancient ciphers, such as Ceaser cipher, machine (or rotor) cipherx during WWI and WWII, and modern ciphers, which play a fundamental role in providing Confidentiality, Integrity, and Authentication services during transmission, processing, and storage of the sensitive data over the open or public networks. [...] Full article

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Cryptography, Volume 1, Issue 1 (June 2017) – 9 articles

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