file extension PEM

File extension PEM description:

PEM is the outgrowth of work by the Privacy and Security Research Group (PSRG) of the IRTF. At the heart of PEM is a set of procedures for transforming RFC 822 messages in such a fashion as to provide integrity, data origin authenticity, and, optionally, confidentiality. PEM may be employed with either symmetric or asymmetric cryptographic key distribution mechanisms. Because the asymmetric (public-key) mechanisms are better suited to the large scale, heterogeneously administered environment characteristic of the Internet, to date only those mechanisms have been standardized. The standard form adopted by PEM is largely a profile of the CCITT X.509 (Directory Authentication Framework) recommendation.

PEM is defined by a series of documents. The first in the series defines the message processing procedures. The second defines the public-key certification system adopted for use with PEM. The third provides definitions and identifiers for various algorithms used by PEM. The fourth defines message formats and conventions for user registration, Certificate Revocation List (CRL) distribution, etc. (The first three of these were previously issued as RFCs 1113, 1114 and 1115. All documents have been revised and are being issued first as Internet-Drafts.)