Digital cash

DIGITAL CASH
What Is Digital Cash?
 Digital cash is a digitally signed payment message that serves as a
medium of exchange

 Since hard currency or paper cash carries total anonymity in
transactions, the term digital cash is coined to refer to anonymous
electronic token based payment systems.

 Digital Cash is meant to work as paper cash.

 Digital Cash is a technical product of anonymous digital commerce in
strategic level.

 There are different implementations of Digital Cash.

 There are several approaches in implementing digital cash: “Simple
Anonymous Cash” by Fiat-Caum-Naor, “Traceable Anonymous Cash” by
Ferguson, the Brands scheme, and “Auditable, Anonymous Electronic
Cash” by Sander-Ta-Shama.

 The introduced methods have advantages and disadvantages. The
Brands scheme provides reasonable security and anonymity; however, it
is more complicated.

Need for Anonymous Digital Cash
 Increase in electronic surveillance by governments and other institutions

 Lack of privacy features associated with ordinary electronic transactions




Motivations
 Comparing to paper cash, paper cash is: slow, vulnerable, costly, and
difficult to transfer.