1. Cryptology/Cryptography
The practice and study of techniques for secure communication in the presence of third parties (called adversaries).

2. Cryptanalysis
The term used for the study of methods for obtaining the meaning of encrypted information without access to the key normally required to do so.
It is the study of how to crack encryption algorithms or their implementations.

4. Encryption
The process of converting ordinary information (called plaintext) into unintelligible text (called ciphertext)

5. Cipher (or cypher)
A pair of algorithms that create the encryption and the reversing decryption.

6. X.509
An ITU-T standard for a public key infrastructure (PKI) and Privilege Management Infrastructure (PMI). X.509 specifies, amongst other things, standard formats for public key certificates, certificate revocation lists, attribute certificates, and a certification path validation algorithm.

7. SSL (Secured Sockets Layer)
Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL), are cryptographic protocols that are designed to provide communication security over the Internet.

8. Issuer
A legal entity that develops, registers and sells securities for the purpose of financing its operations.