Forward-secure digital signature method and system capable of balancing cost

Abstract

The invention belongs to the technical field of information security, and relates to a problem of signing digital information, in particular to a digital signature method and a digital signature system which can reduce the influence on the leakage of a signing key and are more applicable. Compared with a common digital signature, the signature method has a key updating algorithm, and realizes forward security of the signing key, namely, even if a rival obtains the signing key in a current time range, the rival cannot forge a legal signature belonging to the previous time range through the key so as to protect the validity of the previous signatures and reduce the loss caused by the leakage of the key. Besides, according to a specific application condition and on the basis of equivalent security, the scheme can allow a project planner to select proper key storage cost and computation cost according to hardware conditions and make full use of the storage capacity and computation ability of hardware so as to enable the key storage cost and the computation cost to achieve perfect balance.

Description

technical field [0001] The invention belongs to the technical field of information security, and relates to the problem of signing digital information, more precisely, it relates to a method that can reduce the impact of signature key leakage and allow designers to obtain a perfect balance between storage cost and calculation cost according to application requirements. Digital signature method and system. Background technique [0002] The concept of forward security signature was introduced by Anderson in 1997, the purpose is to solve a major flaw of the usual digital signature, that is, once the secret key is lost (or stolen), all the signatures previously generated by this key become invalid. invalid. In order to reduce such losses, Anderson proposes to divide the validity period of the key into periods. At the end of each period, the signer obtains a new secret key for the next period from the secret key of the current period in a one-way mode, and Securely delete secre...

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