In this paper we show that the related key boomerang attack by E. Fleischmann et al. from the paper mentioned in the title does not allow to recover the master key of the GOST block cipher with complexity less than the complexity of the exhaustive search. Next we present modified attacks. Finally we argue that these attacks and the related key approach itself are of extremely limited practical ...

An identity based signature scheme allows any pair of users to communicate securely and to verify each others signatures without exchanging public key certificates. An aggregate signature scheme is a digital signature scheme which supports aggregation of signatures. Batch verification is a method to verify multiple signatures at once. Aggregate signature is useful in reducing both communication...

Recently an algorithmic schema was proposed for converting any existing block cipher into one which excepts variable length inputs with the computational workload increasing in proportion to the block size. The resulting cipher is referred to as an elastic block cipher. The initial work presented immunity to certain key recovery attacks, and left open further analysis of the method and its poss...

The DES has reached the end of its lifetime due to its too short key length and block length (56 and 64 bits respectively). As we are awaiting the new AES, triple (and double) encryption are the common solution. However, several authors have shown that these multiple modes are much less secure than anticipated. The general belief is that these schemes should not be used, as they are not resista...

PAGES is block cipher family based on the design of Speck, see [1]. However, some intriguing design details of Speck were not used in the design of PAGES. PAGES has block size of 256 bit and comes in three version: PAGES-512, PAGES-768, and PAGES-1024, were the number denotes the key length. The number of rounds is 64, 96, or 128, respectively. PAGES uses variables of 128 bit, that is half the ...

The security of interchanged use of modes of operation of block ciphers have not been discussed in the public literature. So far, the modes of operation of block ciphers have been treated as completely independent and uncorrelated. In this paper we represent both CBC and OFB as quasigroup string transformations, and then show that OFB mode is a special case of the CBC mode of operation. That ra...

We consider the question of efficiently extending the key length of block ciphers. To date, the approach providing highest security is triple encryption (used e.g. in Triple-DES), which was proved to have roughly κ+ min{n/2, κ/2} bits of security when instantiated with ideal block ciphers with key length κ and block length n, at the cost of three block-cipher calls per message block. This paper...

PAGES is block cipher family based on the design of Speck, see [1]. However, some intriguing design details of Speck were not used in the design of PAGES. PAGES has block size of 256 bit and comes in three version: PAGES-512, PAGES-768, and PAGES-1024, were the number denotes the key length. The number of rounds is 64, 96, or 128, respectively. PAGES uses variables of 128 bit, that is half the ...

This paper proposes to put forward an innovative algorithm for symmetric key block cipher named as “Triple Prime Symmetric Key Block Cipher with Variable Key-Spaces (TPSKBCVK)” that employs triple prime integers as private key-spaces of varying lengths to encrypt data files. Principles of modular arithmetic have been elegantly used in the proposed idea of the cipher. Depending on observations o...

So far, low probability differentials for the key schedule of block ciphers have been used as a straightforward proof of security against related-key differential analysis. To achieve resistance, it is believed that for cipher with k-bit key it suffices the upper bound on the probability to be 2−k. Surprisingly, we show that this reasonable assumption is incorrect, and the probability should be...