# Section 04: Email Encryption

## Email Encryption

Digital signature

> A digital signature is a mathematical scheme for verifying the authenticity of digital messages or documents. A valid digital signature, where the prerequisites are satisfied, gives a recipient very high confidence that the message was created by a known sender (authenticity), and that the message was not altered in transit (integrity).

SSL (Secure sockets layer)

> Netscape developed the original SSL protocols, and Taher Elgamal, chief scientist at Netscape Communications from 1995 to 1998, has been described as the "father of SSL". SSL version 1.0 was never publicly released because of serious security flaws in the protocol.

TLS (Transport layer security)

> Transport Layer Security (TLS) is a cryptographic protocol designed to provide communications security over a computer network. The protocol is widely used in applications such as email, instant messaging, and voice over IP, but its use in securing HTTPS remains the most publicly visible.

openssl

> OpenSSL is a software library for applications that secure communications over computer networks against eavesdropping or need to identify the party at the other end. It is widely used by Internet servers, including the majority of HTTPS websites.

PGP (Pretty good privacy)

> Pretty Good Privacy (PGP) is an encryption program that provides cryptographic privacy and authentication for data communication. PGP is used for signing, encrypting, and decrypting texts, e-mails, files, directories, and whole disk partitions and to increase the security of e-mail communications.

GnuPG / GPG (GNU privacy guard)

> GNU Privacy Guard (GnuPG or GPG) is a free-software replacement for Symantec's PGP cryptographic software suite. The software is compliant with RFC 4880, the IETF standards-track specification of OpenPGP. Modern versions of PGP are interoperable with GnuPG and other OpenPGP-compliant systems.

Web of trust

> In cryptography, a web of trust is a concept used in PGP, GnuPG, and other OpenPGP-compatible systems to establish the authenticity of the binding between a public key and its owner.

S/MIME (Secure multipurpose internet mail extensions)

> S/MIME (Secure/Multipurpose Internet Mail Extensions) is a standard for public key encryption and signing of MIME data. S/MIME is on an IETF standards track and defined in a number of documents, most importantly RFC 3369, 3370, 3850 and 3851.

Links

* [https://en.wikipedia.org/wiki/Digital\_signature](https://en.wikipedia.org/wiki/Digital_signature)
* [https://en.wikipedia.org/wiki/Transport\_Layer\_Security](https://en.wikipedia.org/wiki/Transport_Layer_Security)
* [https://en.wikipedia.org/wiki/Transport\_Layer\_Security](https://en.wikipedia.org/wiki/Transport_Layer_Security)
* [https://www.openssl.org](https://www.openssl.org)
* [https://en.wikipedia.org/wiki/Pretty\_Good\_Privacy](https://en.wikipedia.org/wiki/Pretty_Good_Privacy)
* [https://en.wikipedia.org/wiki/GNU\_Privacy\_Guard](https://en.wikipedia.org/wiki/GNU_Privacy_Guard)
