Threshold secret information distribution and recovery method and device

Abstract

The invention discloses a threshold secret information distribution method which divides secret information into n-numbered information portions. The method comprises the following steps: dividing secret information into p-1 parts, wherein p is a prime and is not less than n-1; generating (k-1)*(p-1) random information strings; generating a binary operation matrix with (n-k+1)*(n+1) blocks; and generating n-numbered information portions according to the p-1 parts of secret information, the random information strings and the binary operation matrix, and distributing to n-numbered sharers. The invention also discloses a threshold secret information recovery method, wherein when at least random k-numbered information portions are known, secret information is recovered. The invention also discloses a threshold secret information distribution device and recovery device. The closer k is to n, the lower computational loads and higher efficiencies the threshold secret distribution and recovery devices have; and the distribution and recovery of threshold secret information can be completed by the same device.

Description

technical field [0001] The present invention relates to the technical field of information security, in particular to a device and method for allocating and restoring threshold secret information. Background technique [0002] Secret sharing is an important means of information security and data confidentiality, and it plays a key role in the safe storage, transmission and legal utilization of important information and secret data. (k, n) threshold secret sharing concept by Shamir [2] and Blakley [3] It is proposed that the basic idea is that a secret is shared by n people, and it satisfies: ① Only k or more participants can jointly reconstruct the secret; ② Any less than k participants cannot get any information about the secret. A scheme that satisfies ① and ② is called a perfect secret sharing scheme. In addition, if it satisfies ③ the size of the share held by each participant is as large as the original secret, this scheme is called an ideal secret sharing scheme. S...

AI Technical Summary

Problems solved by technology

[0007] 1. When k is closer to n, the calculation amount of secret distribution and restoration of this scheme is larger and the efficiency is lower;

[0008] 2. Even if there are more than k shares participating in the secret restoration, the calculation amount of restoration cannot be reduced;

[0009] 3. Participants are not allowed to choose the shares they hold

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