Trusted third parties in electronic commerce

Trusted third parties (TTPs) are often employed to facilitate trust in commercial transactions. Banks, lawyers and brokers are typical examples in everyday use. On moving to the electronic world the environment for establishing trust is significantly changed and, consequently, TTPs are required to play new roles. important TTP services for electronic commerce include certification, time-stamping and notarisation. This paper describes these new TTP services and the vital roles they play in electronic commerce.