Cryptography is essential to the security of nowadays Internet and interconnected world. Cryptographic algorithms and functions are used to ensure confidentiality, integrity, certifying information and to do authentication in the Internet.
Confidentiality is ensured via encryption, integrity is ensured via cryptographic hash functions. Certification and authentication use mechanisms that are used by encryption and hash functions.
The basic mechanisms in cryptography are:
- symmetric encryption: uses the same (symmetric) key for both encryption and decryption
- public key cryptography: uses a private and a public key with different roles
- key exchange algorithms: ensure valid key exchange when the communication channel is insecure
- cryptographic hash functions: to generate secure message digests that are much smaller than the original message
- random number generators: used to generate unique, secure and random number keys
Cryptography is concerned with protection of data and communication channel. Cryptanalysis is concerned with finding potential flaws in cryptographic systems and algorithms. Both form the field of cryptology.
When developing, maintaining and managing systems and software, it's critical that you account for protection of data and identity via cryptographic primitives. As an ethical hacker you want to assess the proper configuration of good cryptographic primitives.
Attacks of all kinds have rendered some of the cryptographic primitives (or their earlier versions) obsolete.
Working in cryptograhy requires a good understanding of the maths behind it all, the APIs and tools employed and knowing best practices in developing, deploying and assessing IT systems.