Research Of Electronic Cash System Based ACJT Group Signature

Along with computer more popular and Internet more flourishing,more and more people in favor of shopping on Internet because of it's convenience and rapidness.But now the bank service on web we can use is account based.That is bank or shop can know the information about customer.Meanwhile the payment must be online,it means when network crash or bank failure the transaction must be canceled.Absence of Electronic cash give hope to solve these problems.Because Electronic cash is the string that applys digital signature,encryption,identity authentication techniques in cryptography.So it can pay anonymously and offline on Internet,moreover it has high security. It obvious that Electronic cash must be the crucial pay method of Electronic commerce in the future.Due to these problems such as revovable anonymity,divisibility,efficency,dual-payment don't solve very well, the application of Electronic cash is blocking now.This paper aims at the forementioned problems.Electronic cash based ACJT scheme is the research object.In this paper,I propose a new higher secure and efficency Electronic cash scheme. This scheme dedicate to improving efficency, preventing dual-payment in advance,dividing Electronic cash. I have made useful explore for Electronic cash development.Although ACJT scheme is a proved secure and efficient group signature scheme and it is coalition-resistance yet,the bank remains the bottleneck of Electronic cash syetem based ACJT scheme.To change it ,I apply a new Electronic cash model where user is the issuer of Electronic Cash,separate bank function meanwhile improve efficiency of system. Previous Electronic Cash systems based ACJT scheme applying combination shared symmertic crypto pairs and group advisor to prevent blackmailing, so it exists security problem and adds the compute complication of encrypting, moreover the role of group advisor adds the system burden. To improve effiency in preventing blackmailing, user get a alias member certificate when register. Later,user can use the alias member certificate to sign Electronic Cash while someone blackmail him/her.The blackmailer can't recognize this Electronic Cash,but group revoke manager can.So blackmailing can forbid by this means.Divisibility of Electronic Cash worried many researchers so long.Previous Electronic Cash systems not only efficency is low but also the different Electronic Cash parts can link each other.To solve this problem ,I use a smart method that take advantage of order to pay.Additionally,Electronic Cash dual-payment is easy take place because it is easy to copy.The measure in previous systems usually is to limit the payment amout or punish the dual-payment person after revoking his/her anonymity.So whether security or result are not good.I put forward user and shop authentication more times in the process of payment to solve this problem.Finally,I implement this system with JBuilder and SQLServer.This step is great for Electronic Cash application.