A system and method for facilitating electronic commerce by securely providing certificate-related and other services including certificate validation and warranty is disclosed. Services are preferably provided in a four-corner trust model, (see figure 1). The four-corner model comprises a buyer (106) or subscribing customer, and a seller (108) or relying customer, who engage in an on-line transaction. The buyer is a customer of a first financial institution (102) or issuing participant, which is a certificate authority and issues a hardware token including a private key and a signed digital certificate. The seller is a customer of a second financial institution (104) or relying participant, which is a certificate authority and issues a hardware token including a private key and a signed digital certificate. The system also includes a root certificate authority that operates a certificate authority that issues digital certificates to the issuing and relying participants. Each participant and the root entity are preferably provided with a transaction coordinator that provides a single consistent interface for certificate-status messages and requests, as well as messages and requests relating to other services.