公开(公告)号：US20220294605A1

公开(公告)日：2022-09-15

申请号：US17517661

申请日：2021-11-02

Applicant: University of Electronic Science and Technology of China ,  Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China

Inventor： Chunxiang XU ,  Changsong JIANG ,  Yicong DU

IPC: H04L9/00 ,  H04L9/06

Abstract: A blockchain-based public parameter generation method against backdoor attacks, includes: acquiring the hash values of L latest confirmed blocks on a blockchain, and the hash values of the L blocks and a count variable for generation are mapped to an element in a set G via a specified mapping to obtain the generated public parameter; L≥φ, φ is the minimum number to guarantee blockchains' chain quality property; checking whether the generated parameter meets the condition, if not, discarding the parameter and updating the generated public parameter; if the condition is met, outputting the public parameter to the device that uses the public parameter. In this disclosure, the public parameters are random, since they are based on the latest confirmed blocks on the blockchain and are guaranteed by the computational power of the blockchain; the generation of public parameters is publicly verifiable and random.

公开(公告)号：US20210099315A1

公开(公告)日：2021-04-01

申请号：US17032041

申请日：2020-09-25

Applicant: University of Electronic Science and Technology of China

Inventor： Chunxiang XU ,  Chuang LI ,  Yuan ZHANG

IPC: H04L9/32

Abstract: A method for blockchain-based time stamping for digital signature is disclosed. The method includes two participants: a signer who signs a message, a verifier who verifies the message. In the method, the signer obtains hash values of a certain number of latest confirmed blocks in blockchain, binds these hash values and the message together to be a new message. The signer then generates a signature of the new message and inserts identification data of this signature and the new message into a transaction of blockchain. This method ensures that the generation time of the signature is prior to the generation time of the block which contains the signature and, at the same time, is after the generation time of the blocks whose hash values are included in the signature, which produces an accurate time interval for the digital signature.