A principal in a security system trusts another principal if it allows its security to depend on assertions made by that other principal. For example, when a web browser assumes that a web site is legitimate because the site shows a certificate signed by a certificate authority, the browser trusts the CA. Trust is often established and propagated through cryptography. The concept is derived from the plain English meaning of the word, which is studied by social sciences.
- pki: public key infrastructure, a class of systems for establishing trust between a priori unrelated parties, based on central authorities.
- Web of trust: a class of systems for establishing trust between a priori unrelated parties, based on assertions between peers.
- trusted-computing: a series of protocols and designs related to the security of PC-style computers, promoted by the Trusted Computing Group, including the TPM.