Research And Application On Secret Sharing And Proxy Signature

The security issue of keys is the lifeline of the entire cryptogrammic system in the moderncryptography. In order to realize the Key Management, Secret sharing system arises at thehistoric moment. The basic idea is that the key segmentation is distributed to several members,which will greatly reduce the possibility of key exposures. Digital signature is a kind ofimportant authentication methods. As a kind of electronic simulation object, digital signature isdeveloping rapidly and will replace handwritten signatures someday in the future. Signcryptioncan ensure transmission in both confidential and the authentication way and achieve two kinds ofoperation including encryption and signature in one logical step, which will improve agreementefficiency.This paper makes a study of the secret sharing system. The threshold password technology inthe digital proxy signature and sign the application fields are analyzed and discussed, the mainworks is as follows:1. The secret sharing system especially threshold schemes are studied. We design a thresholdsecret sharing scheme, in which the secret dealer is eliminated and the secret shares are providedby every member of the group equally. The scheme can resolve the problem of memberscheating effectively. In addition, this scheme also has the dynamic quality. The operations ofincreasing or decreasing group member are easy to be realized. Finally, some traditionalmonitoring schemes are analyzed and the problem of "once monitor, monitor forever" is solvedeffectively with our method.2. Digital proxy signature scheme is researched. A directional proxy signature scheme isdesigned, which proves the signature scheme meeting common security requirements. Inaddition, in order to improve the safety factor, prior to the security technology is adopted in thisscheme. The decryption key of proxy signer can be updated by this technology. It can ensure theeffectiveness of the previous signature even if the key out. This scheme has anothercharacteristic, only the designated personnel by the Original signer can verify this proxysignature weather is legal or not, others has no right to do it. This characteristic can meet somespecial occasions needs.3. The Double threshold technology is studied. A scheme of double threshold Proxysigncryption is designed in some Realistic background. The scheme can not only meets the usualsigncryption scheme safety requirement, but also adopt double threshold technology. The firstthreshold technology is on key sharing, that can reduces the risk of key leak greatly; the usingobject of second threshold technology is Proxy signcryption user. The signcryption text is signedby a group so that the probility of abusing Proxy signcryption right is reduced.