Public-key Infrastructure - Usage Examples

Usage Examples

PKIs of one type or another, and from any of several vendors, have many uses, including providing public keys and bindings to user identities which are used for:

• Encryption and/or sender authentication of e-mail messages (e.g., using OpenPGP or S/MIME).
• Encryption and/or authentication of documents (e.g., the XML Signature or XML Encryption standards if documents are encoded as XML).
• Authentication of users to applications (e.g., smart card logon, client authentication with SSL). There's experimental usage for digitally signed HTTP authentication in the Enigform and mod_openpgp projects.
• Bootstrapping secure communication protocols, such as Internet key exchange (IKE) and SSL. In both of these, initial set-up of a secure channel (a "security association") uses asymmetric key (a.k.a. public-key) methods, whereas actual communication uses faster symmetric key (a.k.a. secret key) methods.
• Mobile signatures are electronic signatures that are created using a mobile device and rely on signature or certification services in a location independent telecommunication environment.
• Universal Metering Interface (UMI) an open standard, originally created by Cambridge Consultants for use in Smart Metering devices/systems and home automation, uses a PKI infrastructure for security.