• Journal of information and communication convergence engineering
• /
• v.3 no.1
• /
• pp.5-8
• /
• 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.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.7
• /
• pp.1495-1500
• /
• 2011

Dynamic cipher has the property that the key-size, the number of round, and the plain text-size are scalable simultaneously. In this paper we propose the block cipher algorithm which is symmetrical in the dynamic network. We present the method for designing secure Dynamic cipher against meet-in-the-middle attack and linear crytanalysis. Also, we show that the differential cryptanalysis to Dynamic cipher is hard.

• Proceedings of the IEEK Conference
• /
• 2000.07b
• /
• pp.743-746
• /
• 2000

In this paper we propose a new network called Dynamic network for symmetric block ciphers. 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.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2000.10a
• /
• pp.149-152
• /
• 2000

Dynamic Network은 블록 크기와 키 크기, 라운드 수가 동시에 가변이며, 각 라운드에서 서브 블록과 서브 키 사이에 연산이 이루어지지 않는 대칭키 블륵 암호 알고리즘을 위한 기본구조이다. 본 논문에서는 Dynamic Network에 기반한 대칭키 블록 암호 알고리즘을 제안한다. 제안하는 Dynamic Cipher는 임의의 비트 스트링을 키로서 사용할 수 있다. 제안하는 Dynamic Cipher에 차분 분석법과 선형 분석법의 적용이 어려움을 보이고, 대칭키 블록 암호 알고리즘이 만족하여야 할 성질들에 대한 실험 결과들을 제시한다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.1
• /
• pp.165-184
• /
• 2023

The ARX-based lightweight block cipher is widely used in resource-constrained IoT devices due to fast and simple operation of software and hardware platforms. However, there are three weaknesses to ARX-based lightweight block ciphers. Firstly, only half of the data can be changed in one round. Secondly, traditional ARX-based lightweight block ciphers are static structures, which provide limited security. Thirdly, it has poor diffusion when the initial plaintext and key are all 0 or all 1. This paper proposes a new dynamic ARX-based lightweight block cipher to overcome these weaknesses, called DABC. DABC can change all data in one round, which overcomes the first weakness. This paper combines the key and the generalized two-dimensional cat map to construct a dynamic permutation layer P1, which improves the uncertainty between different rounds of DABC. The non-linear component of the round function alternately uses NAND gate and AND gate to increase the complexity of the attack, which overcomes the third weakness. Meanwhile, this paper proposes the round-based architecture of DABC and conducted ASIC and FPGA implementation. The hardware results show that DABC has less hardware resource and high throughput. Finally, the safety evaluation results show that DABC has a good avalanche effect and security.

• The Pure and Applied Mathematics
• /
• v.12 no.2 s.28
• /
• pp.143-152
• /
• 2005

We present a new block cipher called DyC. It consists of four sets (procedures) having the different $2^2,\;2^2,\;2^4$, and $2^8$ one-to-one correspondence functions as the elements. The round key is used to determine exactly one composite function from the possible $2^{16}$ composite functions. DyC supports 8 $\times$ n bit key size, 16 $\times$ m bit block length, and n rounds. We have confirmed that DyC offers security against other well-known advanced cryptanalytic attacks including the slide attacks and interpolation attacks. In this paper, we show several properties of the key schedule of DyC by mathematical analysis.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.12
• /
• pp.3398-3415
• /
• 2023

Internet-of-Things (IoT) is an emerging technology that interconnects millions of small devices to enable communication between the devices. It is heavily deployed across small scale to large scale industries because of its wide range of applications. These devices are very capable of transferring data over the internet including critical data in few applications. Such data is exposed to various security threats and thereby raises privacy-related concerns. Even devices can be compromised by the attacker. Modern cryptographic algorithms running on traditional machines provide authentication, confidentiality, integrity, and non-repudiation in an easy manner. IoT devices have numerous constraints related to memory, storage, processors, operating systems and power. Researchers have proposed several hardware and software implementations for addressing security attacks in lightweight encryption mechanism. Several works have made on lightweight block ciphers for improving the confidentiality by means of providing security level against cryptanalysis techniques. With the advances in the cipher breaking techniques, it is important to increase the security level to much higher. This paper, focuses on securing the critical data that is being transmitted over the internet by PRESENT using key-based dynamic S-Box. Security analysis of the proposed algorithm against other lightweight block cipher shows a significant improvement against linear and differential attacks, biclique attack and avalanche effect. A novel key-based dynamic S-Box approach for PRESENT strongly withstands cryptanalytic attacks in the IoT Network.

• Proceedings of the Korean Information Science Society Conference
• /
• 1998.10a
• /
• pp.615-617
• /
• 1998

본 논문에서는 블록 암호 알고리즘을 위한 새로운 Dynamic-네트워크를 제시한다. Dynamic-네트워크 는 좋은 confusion과 diffusion 메카니즘을 제공한다. 어떠한 Dynamic-네트워크 {{{{ { 2}^{n }-비트(n >=1) }}}}길 이를 갖는 모든 평문을 입력으로 할 수 있으며, 일정 길이 이상의 모든 비트 스트링을 키로 사용할 수 있다.

• Journal of the Korea Society of Computer and Information
• /
• v.13 no.4
• /
• pp.169-175
• /
• 2008

The existing block encryption algorithms have been designed for the encryption key value to be unchanged and applied to the round functions of each block. and enciphered. Therefore, it has such a weak point that the plaintext or encryption key could be easily exposed by differential cryptanalysis or linear cryptanalysis, both are the most powerful methods for decoding block encryption of a round repeating structure. Dynamic cipher has the property that the key-size, the number of round, and the plaintext-size are scalable simultaneously. Dynamic network is the unique network satisfying these characteristics among the networks for symmetric block ciphers. We analyze the strength of Dynamic network for meet-in-the-middle attack, linear cryptanalysis, and differential cryptanalysis. Also, In this paper we propose a new network called Dynamic network for symmetric block ciphers.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.7
• /
• pp.3608-3628
• /
• 2017

Several block cipher modes of operation have been proposed in the literature to protect sensitive information. However, different security analysis models have been presented for attacking them. The analysis indicated that most of the current modes of operation are vulnerable to several attacks such as known plaintext and chosen plaintext/cipher-text attacks. Therefore, this paper proposes a secure block cipher mode of operation to thwart such attacks. In general, the proposed mode combines one-time chain keys with each plaintext before its encryption. The challenge of the proposed mode is the generation of the chain keys. The proposed mode employs the logistic map together with a nonce to dynamically generate a unique set of chain keys for every plaintext. Utilizing the logistic map assures the dynamic behavior while employing the nonce guarantees the uniqueness of the chain keys even if the same message is encrypted again. In this way, the proposed mode called SPCBC can resist the most powerful attacks including the known plaintext and chosen plaintext/cipher-text attacks. In addition, the SPCBC mode improves encryption time performance through supporting parallelized implementation. Finally, the security analysis and experimental results demonstrate that the proposed mode is robust compared to the current modes of operation.