Method and system for encoding and decoding digital message

Abstract

The invention provides a method used in the coding and decoding digital information and a system, comprising: selecting positive integers m, n', wherein m is not smaller than n'; generating a public key including E'(x, ID), wherein E'(x, ID) is the nonlinear mapping function group from (x(1),...x(m), ID(1),...,ID(r)) to (y(1),...y(n')), and ID=(ID(1),...,ID(r)) is the identity identification of the authorization user; aiming at the authorization user with the identity identification ID(k), generating a private key corresponding to the identity identification; then completing the corresponding encrypting / decrypting process or the digital signature verification process. The invention realizes the sharing of one public key of all the users of the complete net, effectively solves the cipher key management problem of the super large scale complex network; greatly reduces the system building cost and the operating management cost without building large authentication center and the private key bank; realizes the integral management of the public key data and the user identification, which brings great convenience for the credit management in the network environment.

Description

technical field [0001] The invention relates to the field of information encoding and decoding, in particular to a public key cryptosystem for encrypting, decrypting, signing and verifying data messages. Background technique [0002] Cryptography is a science and technology that studies encryption and decryption transformations. Usually, people refer to understandable text as plaintext; the unintelligible text transformed from plaintext is called ciphertext. The process of converting plaintext into ciphertext is called encryption; the inverse process, that is, the process of converting ciphertext into plaintext is called decryption. This encryption or decryption transformation is controlled by a key. A cryptographic system used in an open environment should meet the following basic requirements: [0003] Confidentiality: ensure that information is not leaked to unauthorized users; [0004] Integrity: ensuring that information is not modified arbitrarily or deliberately; ...

AI Technical Summary

Problems solved by technology

[0023] The technical problem to be solved by the present invention is to provide a method and device for encoding and decoding digital messages, so as to realize an identity-based public key cryptosystem, which can meet the complex use environment of ultra-large-scale networks, and can comply with the construction of a network trust system needs

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