Applications of conic curves blind signature over Zn in E-cash
环Zn上圆锥曲线的盲签名在电子现金中的应用

Conic analogs of blind signature based on RSA over Z_nwere presented.It could be applied in E-payment system to realize divisible E-cash.The security was based on difficulties in factorizing large integer and computing discrete logarithm on Abel group C_n(a,b).By fetching NAF in calculating the multiples of an element in a group,the amount analog was offered to facilitate their realization in E-payment system.Compared with RSA blind signature over finite field,the conic analog over Z_n greatly shortened the length of secret-key and resisted small private exponent attack.Compared with the counterparts based on elliptic curves over Z_n,the conic analog was easier to accomplish,for they not only reserved the advantages but also advanced more advantages such as convenient plaintext embedding and speedy operation.