scholarly journals Message Authentication Codes from Unpredictable Block Ciphers

2009 ◽  
pp. 267-285 ◽  
Author(s):  
Yevgeniy Dodis ◽  
John Steinberger
Keyword(s):  
Block Ciphers ◽  
Message Authentication ◽  
Authentication Codes ◽  
Message Authentication Codes

scholarly journals ZMAC+ – An Efficient Variable-output-length Variant of ZMAC

2017 ◽  
pp. 306-325 ◽  
Author(s):  
Eik List ◽  
Mridul Nandi
Keyword(s):  
Hash Function ◽  
Block Ciphers ◽  
Message Authentication ◽  
Authentication Codes ◽  
Message Authentication Codes ◽  
Length Variant ◽  
Symmetric Key ◽  
Security Bound

There is an ongoing trend in the symmetric-key cryptographic community to construct highly secure modes and message authentication codes based on tweakable block ciphers (TBCs). Recent constructions, such as Cogliati et al.’s HaT or Iwata et al.’s ZMAC, employ both the n-bit plaintext and the t-bit tweak simultaneously for higher performance. This work revisits ZMAC, and proposes a simpler alternative finalization based on HaT. As a result, we propose HtTBC, and call its instantiation with ZHash as a hash function ZMAC+. Compared to HaT, ZMAC+ (1) requires only a single key and a single primitive. Compared to ZMAC, our construction (2) allows variable, per-query parametrizable output lengths. Moreover, ZMAC+ (3) avoids the complex finalization of ZMAC and (4) improves the security bound from Ο(σ2/2n+min(n,t)) to Ο(q/2n + q(q + σ)/2n+min(n,t)) while retaining a practical tweak space.

New Developments in Quasigroup-Based Cryptography

2014 ◽  
pp. 286-317 ◽  
Author(s):  
Aleksandra Mileva
Keyword(s):  
Building Blocks ◽  
Block Ciphers ◽  
Public Key ◽  
Message Authentication ◽  
Authentication Codes ◽  
New Developments ◽  
Identification Schemes ◽  
Public Key Cryptosystems ◽  
Research Activities ◽  
The Given

This chapter offers an overview of new developments in quasigroup-based cryptography, especially of new defined quasigroup-based block ciphers and stream ciphers, hash functions and message authentication codes, PRNGs, public key cryptosystems, etc. Special attention is given to Multivariate Quadratic Quasigroups (MQQs) and MQQ public key schemes, because of their potential to become one of the most efficient pubic key algorithms today. There are also directions of using MQQs for building Zero knowledge ID-based identification schemes. Recent research activities show that some existing non-quasigroup block ciphers or their building blocks can be represented by quasigroup string transformations. There is a method for generating optimal 4x4 S-boxes by quasigroups of order 4, by which a more optimized hardware implementation of the given S-box can be obtained. Even some block ciphers' modes of operations can be represented by quasigroup string transformations, which leads to finding weaknesses in the interchanged use of these modes.

Hash Functions and Their Applications

2018 ◽  
pp. 66-77
Author(s):  
Kannan Balasubramanian
Keyword(s):  
Hash Function ◽  
Hash Functions ◽  
Digital Signatures ◽  
Message Authentication ◽  
Authenticated Encryption ◽  
Authentication Codes ◽  
Message Authentication Codes ◽  
Message Digest ◽  
Cryptographic Hash Functions

Cryptographic Hash Functions are used to achieve a number of Security goals like Message Authentication, Message Integrity, and are also used to implement Digital Signatures (Non-repudiation), and Entity Authentication. This chapter discusses the construction of hash functions and the various attacks on the Hash functions. The Message Authentication Codes are similar to the Hash functions except that they require a key for producing the message digest or hash. Authenticated Encryption is a scheme that combines hashing and Encryption. The Various types of hash functions like one-way hash function, Collision Resistant hash function and Universal hash functions are also discussed in this chapter.

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