Method and apparatus for generating message summary by ring iterative structure

Abstract

The invention relates to a method and a device for generating information abstract by using a loop iteration structure; wherein, the loop iteration structure and a single compression function form an information abstract function. The loop iteration structure inputs information with any length and outputs information abstract with a fixed length. The method includes that the information is divided into n groups, initial value is set and iteration is carried through on the n groups in sequence through the single compression function; wherein, the input value of the first iteration is the initial value and the first group; when n is equal to or more than 2, the output of the n-1 iteration and the n group are taken as the input of the n iteration; a modular addition operation is carried through on a reverse code output by each iteration and carrying through n+1 iteration on the result and the first group; the n+2 iteration is carried through on the or of the next (n-1) groups and the output of the n+1 iteration to generate the information abstract. The method and device of the invention is safer than an MD iteration structure and can resist a multi-grouping difference attack as well as resist the attack of a D-way second inverse image.

Description

technical field [0001] The present invention relates to the fields of cipher technology and computer technology in information security technology, and more specifically, relates to a method and device for generating a message digest by using a ring iteration structure. Background technique [0002] The development of cryptography has gone through three stages: classical cryptography, symmetric cryptography and public key cryptography. Message digest function (referred to as HASH function) is a low-level technology of digital signature and message authentication code, and it includes two parts: iterative structure and one-way compression function. [0003] At present, the commonly used HASH functions are MD5, SHA-0 and SHA-1, etc. (see literature [1]), they are all based on (MD) iterative structure (see literature [2], [3]), MD iterative structure is a linear iterative structure, such as figure 1 shown. [0004] figure 1 is a schematic diagram of the MD iteration struct...

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