Modern cryptography is the cornerstone of computer and communications security. Its foundation is based on various concepts of mathematics such as number theory, computational-complexity theory, and probability theory.
Characteristics of Modern Cryptography
There are three major characteristics that separate modern cryptography from the classical approach.
| Classic Cryptography | Modern Cryptography |
|---|---|
| It manipulates traditional characters, i.e., letters and digits directly. | It operates on binary bit sequences. |
| It is mainly based on ‘security through obscurity’. The techniques employed for coding were kept secret and only the parties involved in communication knew about them. | It relies on publicly known mathematical algorithms for coding the information. Secrecy is obtained through a secrete key which is used as the seed for the algorithms. The computational difficulty of algorithms, absence of secret key, etc., make it impossible for an attacker to obtain the original information even if he knows the algorithm used for coding. |
| It requires the entire cryptosystem for communicating confidentially. | Modern cryptography requires parties interested in secure communication to possess the secret key only. |