Unformatted text preview: II, Certificate-Based Key Management. This document defines a supporting key management architecture and infrastructure, based on public-key certificate techniques to provide keying information to message originators and recipients. — RFC 1423: Part III, Algorithms, Modes, and Identifiers. This document provides definitions, formats, references, and citations for cryptographic algorithms, usage modes, and associated identifiers and parameters. — RFC 1424: Part IV, Key Certification and Related Services. This document describes three types of service in support of PEM: key certification, certificate revocation list (CRL) storage, and CRL retrieval. Certificates
PEM is compatible with the authentication framework described in ; see also . PEM is a superset of X.509; it establishes procedures and conventions for a key-management infrastructure for use with PEM and with other protocols (from both the TCP/IP and OSI suites) in the future. The key-management infrastructure establishes a single root for all Internet certification. The Internet Policy Registration Authority (IPRA) establishes global policies that apply to all certification under this hierarchy. Beneath the IPRA root are Policy Certification Authorities (PCAs), each of which establishes and publishes its policies for registering users or organizations. Each PCA is certified by the IPRA. Below PCAs, CAs certify users and subordinate organizational entities (such as departments, offices, subsidiaries). Initially, the majority of users are expected to be registered with some organization. Some PCAs are expected to provide certification for users who wish to register independent of any organization. For users who wish anonymity while taking advantage of PEM privacy facilities, one or more PCAs are expected to be established with policies that allow for registration of users who do not wish to disclose their identities. PEM Messages
PEM’s heart is its message format. Figure 24.4 shows an encrypted message using symmetric key management, Figure 24....
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- Fall '10
- Cryptography, Bruce Schneier, Applied Cryptography, EarthWeb, Search Search Tips