China Iwncomm Co., Ltd.

Zhiyong Li

Xiang Yan

Jun Cao

Hongtao Wan

Disclosed are a method and device for generating a digital signature. The method comprises: a device generating a digital signature parameter r that meets an effective determining condition; generating a digital signature parameter s according to the following formula s=((1+d)&#xb7;(r+k)&#x2212;r)mod n, by using a private key d, a random number k, r, and an elliptic curve parameter n, a value range of k being [1, n&#x2212;1]; determining if the generated s is 0; if s is 0, regenerating r that meets the effective determining condition, and regenerating s by using d, the regenerated k with the value range of [1, n&#x2212;1] and the regenerated r and n, until s is not 0; converting data types of r and s that is not 0 into byte strings, to obtain a digital signature (r, s). According to the technical solutions provided by embodiments of this application, a digital signature parameter s is obtained by using a simplified calculation formula, and the number of times that big integers are calculated can be reduced, so that the calculation efficiency of generating a digital signature based on an SM2 digital signature generation algorithm is improved.

Method and device for generating digital signature

Disclosed are a method for conducting data encryption and decryption using a symmetric cryptography algorithm and a table look-up device. The method comprises: when it is determined that it is required to use S-boxes to look up a table in a symmetric cryptography algorithm, determining all types of S-boxes to be used; for each type of S-box, determining the total number Nof the type of S-box, and when Nis larger than 1, determining that the type of S-box meets a multiplexing condition; and when data encryption and decryption are conducted using the symmetric cryptography algorithm, multiplexing at least one type of S-box which meets the multiplexing condition. The present application can reduce the occupation by the symmetric cryptography algorithm of hardware resources under the condition of comparative shortage of hardware resources.

Method for conducting data encryption and decryption using symmetric cryptography algorithm and table look-up device

The invention relates to the technical field of information, and disclosed in the present invention are a key negotiation method and apparatus according to the SM2 key exchange protocol. The method is implemented as follows: two negotiation parties both calculate a parameter W according to the minimum positive integer value in the permissible values of X which enable an inequality n&#x2266;2to hold, and perform key negotiation with the opposite negotiation party according to the parameter W. Compared with a method for calculating the parameter W through calculating log 2 (n) logarithmic value firstly and then rounding up the logarithmic value, the method disclosed by the invention has the advantages that the calculated amount is effectively reduced, and the implementation complexity of an algorithm is reduced, thereby greatly improving the implementation efficiency of the key negotiation process based on the SM2 key exchange protocol, and then optimizing the engineering implementation of the SM2 key exchange protocol.

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Xi'an, China

Zhiyong Li