• Title, Summary, Keyword: block cipher

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Differential Fault Analysis on Symmetric SPN Block Cipher with Bitslice Involution S-box (비트 슬라이스 대합 S-박스에 의한 대칭 SPN 블록 암호에 대한 차분 오류 공격)

  • Kang, HyungChul;Lee, Changhoon
    • KIPS Transactions on Computer and Communication Systems
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    • v.4 no.3
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    • pp.105-108
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    • 2015
  • In this paper, we propose a differential fault analysis on symmetric SPN block cipher with bitslice involution S-box in 2011. The target block cipher was designed using AES block cipher and has advantage about restricted hardware and software environment using the same structure in encryption and decryption. Therefore, the target block cipher must be secure for the side-channel attacks. However, to recover the 128-bit secret key of the targer block cipher, this attack requires only one random byte fault and an exhausted search of $2^8$. This is the first known cryptanalytic result on the target block cipher.

Counter Chain: A New Block Cipher Mode of Operation

  • El-Semary, Aly Mohamed;Azim, Mohamed Mostafa A.
    • Journal of Information Processing Systems
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    • v.11 no.2
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    • pp.266-279
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    • 2015
  • In this paper, we propose a novel block cipher mode of operation, which is known as the counter chain (CC) mode. The proposed CC mode integrates the cipher block chaining (CBC) block cipher mode of operation with the counter (CTR) mode in a consistent fashion. In the CC mode, the confidentiality and authenticity of data are assured by the CBC mode, while speed is achieved through the CTR mode. The proposed mode of operation overcomes the parallelization deficiency of the CBC mode and the chaining dependency of the counter mode. Experimental results indicate that the proposed CC mode achieves the encryption speed of the CTR mode, which is exceptionally faster than the encryption speed of the CBC mode. Moreover, our proposed CC mode provides better security over the CBC mode. In summary, the proposed CC block cipher mode of operation takes the advantages of both the Counter mode and the CBC mode, while avoiding their shortcomings.

Impossible Differential Cryptanalysis on DVB-CSA

  • Zhang, Kai;Guan, Jie;Hu, Bin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.4
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    • pp.1944-1956
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    • 2016
  • The Digital Video Broadcasting-Common Scrambling Algorithm is an ETSI-designated algorithm designed for protecting MPEG-2 signal streams, and it is universally used. Its structure is a typical hybrid symmetric cipher which contains stream part and block part within a symmetric cipher, although the entropy is 64 bits, there haven't any effective cryptanalytic results up to now. This paper studies the security level of CSA against impossible differential cryptanalysis, a 20-round impossible differential for the block cipher part is proposed and a flaw in the cipher structure is revealed. When we attack the block cipher part alone, to recover 16 bits of the initial key, the data complexity of the attack is O(244.5), computational complexity is O(222.7) and memory complexity is O(210.5) when we attack CSA-BC reduced to 21 rounds. According to the structure flaw, an attack on CSA with block cipher part reduced to 21 rounds is proposed, the computational complexity is O(221.7), data complexity is O(243.5) and memory complexity is O(210.5), we can recover 8 bits of the key accordingly. Taking both the block cipher part and stream cipher part of CSA into consideration, it is currently the best result on CSA which is accessible as far as we know.

Security Analysis on Block Cipher XSB (블록 암호 XSB에 대한 안전성 분석)

  • Lee, Changhoon
    • KIPS Transactions on Computer and Communication Systems
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    • v.2 no.7
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    • pp.311-316
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    • 2013
  • 256-bit block cipher XSB(eXtended Spn Block cipher) was proposed in 2012 and has a symmetric strucrure in encryption and decryption process. In this paper, we propose a differential fault analysis on XSB. Based on a random byte fault model, our attack can recover the secret key of XSB by using only two random byte fault injection. This result is the first known cryptanalytic result on the target algorithm.

Differential Related-Cipher Attacks on Block Ciphers with Flexible Number of Rounds (가변 라운드 수를 갖는 블록 암호에 대한 차분 연관 암호 공격)

  • Sung Jaechul;Kim Jongsung;Lee Changhoon
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.15 no.1
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    • pp.77-86
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    • 2005
  • Related-Cipher attack was introduced by Hongjun Wu in 2002. We can consider related ciphers as block ciphers with the same round function but different round number and their key schedules do not depend on the total round number. This attack can be applied to block ciphers when one uses some semi-equivalent keys in related ciphers. In this paper we introduce differential related-cipher attacks on block ciphers, which combine related-cipher attacks with differential cryptanalysis. We apply this attack to the block cipher ARIA and SC2000. Furthermore, related-cipher attack can be combined with other block cipher attacks such as linear cryptanalysis, higher-order differential cryptanalysis, and so on. In this point of view we also analyze some other block ciphers which use flexible number of rounds, SAFER++ and CAST-128.

A Study on a Method of Identifying a Block Cipher Algorithm to Increase Ransomware Detection Rate (랜섬웨어 탐지율을 높이기 위한 블록암호 알고리즘 식별 방법에 관한 연구)

  • Yoon, Se-won;Jun, Moon-seog
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.28 no.2
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    • pp.347-355
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    • 2018
  • Ransomware uses symmetric-key algorithm such as a block cipher to encrypt users' files illegally. If we find the traces of a block cipher algorithm in a certain program in advance, the ransomware will be detected in increased rate. The inclusion of a block cipher can consider the encryption function will be enabled potentially. This paper proposes a way to determine whether a particular program contains a block cipher. We have studied the implementation characteristics of various block ciphers, as well as the AES used by ransomware. Based on those characteristics, we are able to find what kind of block ciphers have been contained in a particular program. The methods proposed in this paper will be able to detect ransomware with high probability by complementing the previous detection methods.

IP Design of Corrected Block TEA Cipher with Variable-Length Message for Smart IoT

  • Yeo, Hyeopgoo;Sonh, Seungil;Kang, Mingoo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.2
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    • pp.724-737
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    • 2020
  • Corrected Block TEA(or XXTEA) is a block cipher designed to correct security weakness in the original block TEA in 1998. In this paper, XXTEA cipher hardware which can encrypt or decrypt between 64-bit and 256-bit messages using 128-bit master key is implemented. Minimum message block size is 64-bit wide and maximal message block size is 256-bit wide. The designed XXTEA can encrypt and decrypt variable-length message blocks which are some arbitrary multiple of 32 bits in message block sizes. XXTEA core of this paper is described using Verilog-HDL and downloaded on Vertex4. The operation frequency is 177MHz. The maximum throughput for 64-bit message blocks is 174Mbps and that of 256-bit message blocks is 467Mbps. The cryptographic IP of this paper is applicable as security module of the mobile areas such as smart card, internet banking, e-commerce and IoT.

An Implementation of 128bit Block Cipher Algorithm for Electronic Commerce (전자상거래를 위한 128비트 블록 암호 알고리즘의 구현)

  • 서장원;전문석
    • The Journal of Society for e-Business Studies
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    • v.5 no.1
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    • pp.55-73
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    • 2000
  • Recently; EC(Electronic Commerce) is increasing with high speed based on the expansion of Internet. EC which is done on the cyber space through Internet has strong point like independence from time and space. On the contrary, it also has weak point like security problem because anybody can access easily to the system due to open network attribute of Internet. Therefore, we need the solutions that protect the security problem for safe and useful EC activity. One of these solutions is the implementation of strong cipher algorithm. NC(Nonpolynomial Complete) cipher algorithm proposed in this paper is good for the security and it overcome the limit of current 64bits cipher algorithm using 128bits key length for input, output and encryption key, Moreover, it is designed for the increase of calculation complexity and probability calculation by adapting more complex design for subkey generation regarded as one of important element effected to encryption. The result of simulation by the comparison with other cipher algorithm for capacity evaluation of proposed NC cipher algorithm is that the speed of encryption and decryption is 7.63 Mbps per block and the speed of subkey generation is 2,42 μ sec per block. So, prosed NC cipher algorithm is regarded as proper level for encryption. Furthermore, speed of subkey generation shows that NC cipher algorithm has the probability used to MAC(Message Authentication Code) and block implementation of Hash function.

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Dynamic Network using Symmetric Block Cipher

  • Park Jong-Min
    • Journal of information and communication convergence engineering
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    • v.3 no.1
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    • pp.5-8
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    • 2005
  • Dynamic cipher has the property that the key-size, the number of round, and the plaintext-size are scalable simultaneously. We present the method for designing secure Dynamic cipher against meet-in-the-middle attack and linear cryptanalysis. Also, we show that the differential cryptanalysis to Dynamic cipher is hard. In this paper we propose a new network called Dynamic network for symmetric block ciphers.

Modified Feistel Network Block Cipher Algorithm (변형 피스탈 네트워크 블록 암호 알고리즘)

  • Cho, Gyeong-Yeon;Song, Hong-Bok
    • Journal of the Korea Computer Industry Society
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    • v.10 no.3
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    • pp.105-114
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    • 2009
  • In this paper a modified Feistel network 128 bit block cipher algorithm is proposed. The proposed algorithm has a 128, 196 or 256 bit key and it updates a selected 32 bit word from input value whole by deformed Feistel Network structure. Existing of such structural special quality is getting into block cipher algorithms and big distinction. The proposed block cipher algorithm shows much improved software speed compared with international standard block cipher algorithm AES and domestic standard block cipher algorithm SEED and ARIA. It may be utilized much in same field coming smart card that must perform in limited environment if use these special quality.

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