Abstract

This is paper presents a complete view on working of payment transaction by E-cash. Cryptography used in this process finds the double spending and forgery of E-cash which is nothing but digital information. The digital information specified as E-cash contains the identity of buyer. Bank maintains all information involved in E-cash notes for every user.

The process of transaction involves three participants i.e, bank (who signs E-cash notes),buyer (who uses E-cash),seller(who deposits the notes). The cryptography techniques used in E-cash payment system is digital signature. After signing by bank only cash will valid for payment. Both seller and buyer equipped with public key of bank.

Before each and every transaction a secured connection established between every two participants by symmetric cryptography (common secret key). Thus the system achieves payment process without any third party involvement. And also E-cash notes work like conventional money (coins and notes) because a seller can verify the validity of E-cash notes. The main concept used in each note is RIS (random identity string).