Design And Implementation Of Secret Sharing Algorithm With Chaotic Characteristics

With the development of internet technology, the servers in Internet haveplayed an increasingly important role in human life. In the application, it isimportant to ensure the security and availability of information when peopleexchange important information in the Internet.The traditional method to protect private data is to transport encrypted data inthe internet. However, if the encryption data is loss in the procedure of transaction,the receiver cannot recover the secret. In this way, the (k, n) secret sharing schemecan be used. The receiver can recover secret by only k pieces shadow information.In this thesis Shamir’s secret sharing schemes is studied. However, whenapplied to secret picture, the shadow pictures, i.e., the shares, will leak the profile ofthe secret picture. I propose an improved Shamir’s secret sharing scheme byintroducing chaos theory in the procedure of secret sharing. The security of theimproved Shamir’s secret sharing scheme enhance this of traditional Shamir’s secretmethod. However, this scheme cannot reduce the time complexity and spacecomplexity of Shamir’s secret sharing scheme.In order to reduce time complexity and space complexity of secret sharingscheme. One secret sharing scheme named Maximum Likelihood Estimation basedSecret Sharing Scheme(MLEBSSS) is proposed in this thesis. Compared with linedbased secret sharing scheme, including Shamir’s Scheme, the MLEBSSS is moreefficient both in time complexity and space complexity. However, the security ofthis scheme is weaker.Since the recovery procedure of MLEBSSS is so simple, the assailant canrecover secret information if he has enough shadow pictures. So we improve thissecret sharing scheme to make it more secure. The improved procedure is introducedby two steps. First, we introduce the bit-based protected scheme. Encrypt theshadow pictures by one fixed key, the assailant cannot recover secret picture simply.However, the key space in this protected secret sharing scheme is limited. Theassailant can get the key by brute force attack. Second, using the bit-based above,we encrypt the shadow pictures by introducing chaos theory. The assailant cannotrecover the secret key by brute force attack.We compare this MLEBSSS algorithm with current algorithm in this thesis.The result proves the MLEBSSS algorithm has greater space of application.