What is the difference between s/mime ,tsp and pgp

Question

What is the difference between s/mime ,tsp and pgp? Reference : Bouncycastle.

Bouncycastle has packages for all of them, just don't understand what is the difference and what is the purspose of each package

Answer 1

• S/MIME means Secure/Multipurpose Internet Mail Extensions. It is a standard for public key encryption and signing of MIME data. Mostly used in email. It uses certificate authorities issuing certificates for users, similar to how SSL certificates work.

• PGP means Pretty Good Privacy. It is a data encryption and decryption software that provides cryptographic privacy and authentication for data communication. It follows the OpenPGP standard. Also used in email, among other things. It uses a decentralized network of trust. No certificate authorities.

• TSP is a lot of things.

Answer 2

In addition to Zed's answer, TSP stands for Timestamping protocol, defined in RFC 3161. As is this protocol is not very usable. It's used as a third-party proof of signing time in CMS, CAdES, PDF signatures, PAdES and XAdES. Note, that Authenticode doesn't use TSP for timestamping (another format is used).

Answer 3

Both S/MIME and the PGP mail system uses the hybrid cryptography.But they use different formats for key exchange. Wile PGP depends upon each user’s key exchange, S/MIME uses hierarchically validated certifier for key exchange.PGP was developed to address the security issues of plain text messages. But S/MIME is designed to secure all kinds of attachments/data files. currently S/MIME dominates the modern mail system due to the complexity of implementing PGP mail system. i can not say anything about TSP before knowing further details about it.