There are a lot of security issues in block cipher algorithm.Security analysis and enhanced design of a dynamic block cipher was proposed.Firstly,the safety of ciphertext was enhanced based on confusion substitution o...There are a lot of security issues in block cipher algorithm.Security analysis and enhanced design of a dynamic block cipher was proposed.Firstly,the safety of ciphertext was enhanced based on confusion substitution of S-box,thus disordering the internal structure of data blocks by four steps of matrix transformation.Then,the diffusivity of ciphertext was obtained by cyclic displacement of bytes using column ambiguity function.The dynamic key was finally generated by using LFSR,which improved the stochastic characters of secret key in each of round of iteration.The safety performance of proposed algorithm was analyzed by simulation test.The results showed the proposed algorithm has a little effect on the speed of encryption and decryption while enhancing the security.Meanwhile,the proposed algorithm has highly scalability,the dimension of S-box and the number of register can be dynamically extended according to the security requirement.展开更多
In order to ensure the security of cloud storage, on the basis of the analysis of cloud storage security requirements, this paper puts forward a kind of＂ hidden mapping hyper-combined public key management scheme...In order to ensure the security of cloud storage, on the basis of the analysis of cloud storage security requirements, this paper puts forward a kind of＂ hidden mapping hyper-combined public key management scheme based on the hyperelliptic curve crypto system, which is applicable to the distributed cloud storage. A series of operation processes of the key management are elaborated, including key distribution, key updating and key agreement, etc. Analysis shows that the scheme can solve the problem of large-scale key management and storage issues in cloud storage effectively. The scheme feathers high efficiency and good scalability. It is able to resist collusion attack and ensure safe and reliable service provided by the cloud storaee system展开更多
Unified Irrpossible Differential （UID） cryptanalysis is a systeimtic method for finding impossible differentials for block ciphers. Regarding to the problem of automatically retrieving the impossible differential ch...Unified Irrpossible Differential （UID） cryptanalysis is a systeimtic method for finding impossible differentials for block ciphers. Regarding to the problem of automatically retrieving the impossible differential characteristics of block ciphers, with the use of particular intermediate difference state expression, UID gets the same or better results compared with other present cryptanalysis results. ARIA is a Korean block cipher expecting that there are no impossible differentials on four or rmre rounds. Based on a property of the Diffusion layer （DL） of ARIA, a specific selection is used before conflict searching to optimize. UID is applied to ARIA, and 6 721 impossible differential chains are found. The length of those chains is four rounds, the same as eisting results, but more varied in form Moreover, ARIA is a Substitution-Penmtation Network （SPN）, not a Feistel structure or generalized Feistel structure as UID was applied to before.展开更多
基金supported in part by National Natural Science Fundation of China under Grant No.61202458,61403109
文摘There are a lot of security issues in block cipher algorithm.Security analysis and enhanced design of a dynamic block cipher was proposed.Firstly,the safety of ciphertext was enhanced based on confusion substitution of S-box,thus disordering the internal structure of data blocks by four steps of matrix transformation.Then,the diffusivity of ciphertext was obtained by cyclic displacement of bytes using column ambiguity function.The dynamic key was finally generated by using LFSR,which improved the stochastic characters of secret key in each of round of iteration.The safety performance of proposed algorithm was analyzed by simulation test.The results showed the proposed algorithm has a little effect on the speed of encryption and decryption while enhancing the security.Meanwhile,the proposed algorithm has highly scalability,the dimension of S-box and the number of register can be dynamically extended according to the security requirement.
基金This work was supported in part by the National Science Foundation Project of P.R.China，the Fundamental Research Funds for the Central Universities under Grant No.FRF-TP-14-046A2
文摘In order to ensure the security of cloud storage, on the basis of the analysis of cloud storage security requirements, this paper puts forward a kind of＂ hidden mapping hyper-combined public key management scheme based on the hyperelliptic curve crypto system, which is applicable to the distributed cloud storage. A series of operation processes of the key management are elaborated, including key distribution, key updating and key agreement, etc. Analysis shows that the scheme can solve the problem of large-scale key management and storage issues in cloud storage effectively. The scheme feathers high efficiency and good scalability. It is able to resist collusion attack and ensure safe and reliable service provided by the cloud storaee system
基金Acknowledgements This paper was supported by the National Natural Science Foundation of China under Ccant No.61073149 the Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20090073110027.
文摘Unified Irrpossible Differential （UID） cryptanalysis is a systeimtic method for finding impossible differentials for block ciphers. Regarding to the problem of automatically retrieving the impossible differential characteristics of block ciphers, with the use of particular intermediate difference state expression, UID gets the same or better results compared with other present cryptanalysis results. ARIA is a Korean block cipher expecting that there are no impossible differentials on four or rmre rounds. Based on a property of the Diffusion layer （DL） of ARIA, a specific selection is used before conflict searching to optimize. UID is applied to ARIA, and 6 721 impossible differential chains are found. The length of those chains is four rounds, the same as eisting results, but more varied in form Moreover, ARIA is a Substitution-Penmtation Network （SPN）, not a Feistel structure or generalized Feistel structure as UID was applied to before.
