A formal structure that enables the user of an inherently insecure public network, such as the Internet, to electronically transfer information, funds, and other sensitive materials through the use of encryption key pairs obtained from and shared through a trusted entity. A certificate authority (CA) issues and verifies digital certificates that contain an encryption key and attest to the authenticity of the transaction party. A registration authority (RA) verifies the CA prior to the issuance of a digital certificate to the requesting party. See also authentication, CA, digital certificate, encryption, Internet, key, private key, public key, and RA.