PGP vs S Multipurpose Internet Mail Extensions

Came across an excellent and lucid blog on PGP/MIME and S/MIME - a choice many of us struggle with. Thanks Aaron Toponce! A small relevant extract from the blog is posted below for quick brief


PGP/MIME

1. Uses the OpenPGP RFCs and standards.
2. The “signature.asc” detached signature is in plain text.
3. Flexibility in algorithm choice for encryption, signing and compression.
4. Relies on a distributed trust model.
5. Not as widely deployed in MUAs as S/MIME.
6. Public key must be distributed separately from the signature.
7. Trivial to integrate with webmail providers.
8. Can only be used with signing documents.
9. An expiration date does not need to be set on the public key.
10. Free.

S/MIME

1. Based on a number of RFCs and standards.
2. The “smime.p7s” detached signature is in a binary format.
3. Generally, the Certificate Authority (CA) chooses the algorithm and key size.
4. Relies on a centralized trust model.
5. More widely deployed than PGP/MIME
6. Public certificate distributed in each detached signature.
7. Difficult to integrate with webmail providers.
8. Can be used for both signatures and encryption.
9. Generally, the public certificate expires once per year.
10. Some CAs provide certs free for personal use, but most if not all CAs charge for professional use. As low as $20 per year, depending on the CA.