Cipher PRESENT Research Articles

Generalization of Matsui’s Algorithm 1 to linear hull for key-alternating block ciphers

We consider linear approximations of an iterated block cipher in the presence of several strong linear approximation trails. While the effect of such trails in Matsui's Algorithm 2, also called the linear hull effect, has been previously studied by a number of authors, their effect on Matsui's Algorithm 1 has not been investigated until now. The goal of this paper is to fill this gap and examine how to generalize Matsui's Algorithm 1 to work also on linear hulls. We restrict to key-alternating ciphers and develop a mathematical framework for this kind of attacks. The complexity of the attack increases with the number of linear trails that have significant contribution to the correlation. We show how to reduce the number of trails and thus the complexity using related keys. Further, we illustrate our theory by experimental results on a reduced round version of the block cipher PRESENT.

Rectified Differential Cryptanalysis of 16 Round Present

In this paper, we have suggested rectifications in differential cryptanalysis of ultra-lightweight block cipher PRESENT reduced to 16 rounds. We have shown that proposed differential attack by Wang [3] on 16 round PRESENT can recover at the most 30 subkey bits, although the author has claimed to recover 32 bits of subkey for last two rounds. We have also computed data complexity and success probability for recovering 30 subkey bits accordingly by the differential attack on 16 round PRESENT.

A comparative study of hardware architectures for lightweight block ciphers

A hardware-based performance comparison of lightweight block ciphers is conducted in this paper. The DESL, DESXL, CURUPIRA-1, CURUPIRA-2, HIGHT, PUFFIN, PRESENT and XTEA block ciphers have been employed in this comparison. Our objective is to survey what ciphers are suitable for security in Radio Frequency Identification (RFID) and other security applications with demanding area restrictions. A general architecture option has been followed for the implementation of all ciphers. Specifically, a loop architecture has been used, where one basic round is used iteratively. The basic performance metrics are the area, power consumption and hardware resource cost associated with the implementation resulting throughput of each cipher. The most compact cipher is the 80-bit PRESENT block cipher with a count of 1704GEs and 206.4Kbps, while the largest in area cipher is the CURUPIRA-1. The CURUPIRA-1 cipher consumes the highest power of 118.1μW, while the PRESENT cipher consumes the lowest power of 20μW. All measurements have been taken at a 100kHz clock frequency.

Research on Fault-Electromagnetic Attack on Block Cipher

It is one of the important factors in iterative block ciphers design that proper rounds are used to resist differential analysis, linear analysis and many other kinds of attack. Block ciphers usually adopt loop codes in software and repetition structures in hardware in order to reduce complexity and cost. This paper presents an effective fault-electromagnetic attack which can change the rounds of block ciphers in running process, by inducing appropriate fault to the cryptographic chip. The executing rounds of the attacked block cipher can be detected from the electromagnetic radiation track of cryptographic chip. Then the secret key can be deduced directly or with simple mathematical analysis. The simulation result of lightweight block cipher PRESENT shows that the suggested attack is feasible and efficient, when it is implemented with single chip microcomputer. Furthermore, countermeasures are given to resist this kind of attack.

Side-Channel Resistant Crypto for Less than 2,300 GE

A provably secure countermeasure against first order side-channel attacks was proposed by Nikova et al. (P. Ning, S. Qing, N. Li (eds.) International conference in information and communications security. Lecture notes in computer science, vol. 4307, pp. 529–545, Springer, Berlin, 2006). We have implemented the lightweight block cipher PRESENT using the proposed countermeasure. For this purpose we had to decompose the S-box used in PRESENT and split it into three shares that fulfill the properties of the scheme presented by Nikova et al. (P. Lee, J. Cheon (eds.) International conference in information security and cryptology. Lecture notes in computer science, vol. 5461, pp. 218–234, Springer, Berlin, 2008). Our experimental results on real-world power traces show that this countermeasure provides additional security. Post-synthesis figures for an ASIC implementation require only 2,300 GE, which makes this implementation suitable for low-cost passive RFID-tags.

Permutation code encryption—New achievement based on path encryption

By researching into the attack to present block cipher, we find an essential reason leading to the assailable encryption strength, set up a new block cipher idea and put forward a block cipher encryption concept path encryption. We present permutation code encryption which is based on path encryption. Now permutation code encryption is a patent of Chinese invention. In Permutation Code Encryption, we use a pseudo-random sequence of the keys to control the paths. The simulation result shows that forn-bit block the encryption strength is novel higher than 2″ and the algorithm can finish the encryption of one block in 7.5 ns, which is unrelated with the block length.

A POLYGRAPHIC SUBSTITUTION CIPHER BASED ON MULTIPLE INTERLOCKING APPLICATIONS OF PLAYFAIR

This paper presents a non-numerical polygraphic substitution cipher which appears more efficient than Hill's algebraic system. For instance, by using the same number of “operations” per message as a 6-graphic algebraic substitution cipher, the present cipher can achieve 4096-graphic substitution. Less dramatically, a 16-graphic application of the present cipher requires only one-eighth as many operations as a 16-graphic algebraic cipher. The source of the greater efficiency of the proposed cipher is that the number of letters which can be jointly enciphered is exponential, rather than linear, with respect to the number of operations performed.