A Divisible and Transferable Digital Cash Protocol
Digital cash is an electronic payment system which enables a secure off-line transaction without revealing the payer's identity. In this paper, the authors present a k-term extension of the brands digital cash protocol which uses a simple and efficient verifiable secret sharing scheme for the implementation of k-term digital coins. The user anonymity is revoked in the event of over-expenditure of digital coins i.e., when k+1 payments are made using a k-term coin. In their scheme, the transferability is also incorporated into the digital cash protocol with the help of the Trusted Third Party without any increase in the digital cash size with each transaction.