E-Mail Security Applications

Several applications employing various cryptographic techniques have been developed to provide confidentiality, integrity, authentication, non-repudiation, and access control for e-mail communications.

Secure Multipurpose Internet Mail Extensions (S/MIME)

Secure Multipurpose Internet Mail Extensions (S/MIME) is a secure method of sending e-mail incorporated into several popular browsers and e-mail applications. S/MIME provides confidentiality and authentication by using the RSA asymmetric key system, digital signatures, and X.509 digital certificates. S/MIME complies with the Public Key Cryptography Standard (PKCS) #7 format and has been proposed as a standard to the Internet Engineering Task Force (IETF).

MIME Object Security Services (MOSS)

MIME Object Security Services (MOSS) provides confidentiality, integrity, identification and authentication, and non-repudiation by using MD2 or MD5, RSA asymmetric keys, and DES. MOSS has not been widely implemented on the Internet.

Privacy Enhanced Mail (PEM)

Privacy Enhanced Mail (PEM) was proposed as a PKCS-compliant standard by the IETF but hasn’t been widely implemented on the Internet. It provides confidentiality and authentication by using 3DES for encryption, MD2 or MD5 message digests, X.509 digital certificates, and the RSA asymmetric system for digital signatures and secure key distribution.

Pretty Good Privacy (PGP)

Pretty Good Privacy (PGP) is a popular e-mail encryption application. It provides confidentiality and authentication by using the IDEA Cipher for encryption and the RSA asymmetric system for digital signatures and secure key distribution. Instead of a central Certificate Authority (CA), PGP uses a trust model, which is ideally suited to smaller groups for validation of user identity.

Today, there are two basic versions of PGP software available. Freeware versions are available from PGP International at www.pgpi.org, and commercial versions are available from PGP Corporations at www.pgp.com. There is also an open-source version, called GPG, available at www.gnupg.org.

 Instant Answer   PGP is a freeware e-mail security application (free to individuals, not organizations) that uses the IDEA algorithm (symmetric) for encryption and the RSA algorithm (asymmetric) for key distribution and digital signatures.