

t is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. For example, with a left shift of 3, D would be replaced by A, E would become B, and so on.
Kerberos was originally developed for Project Athena at the Massachusetts Institute of Technology (MIT). The name Kerberos was taken from Greek mythology; Kerberos (Cerberus) was a three-headed dog who guarded the gates of Hades. The three heads of the Kerberos protocol represent a client, a server and a Key Distribution Center (KDC), which acts as Kerberos' trusted third-party authentication service.
If you want a computer to be perfectly secure, you could fill it with concrete and dump it in the ocean. This would protect any information on the computer from inappropriate use. Unfortunately, the computer would be completely unusable, so you probably don't want to do that! Since you want to both use your computer and keep it safe, you should practice good computer security. Computer security allows you to use the computer while keeping it safe from threats.
Blom's scheme is a symmetric threshold key exchange protocol in cryptography. ... A trusted party gives each participant a secret key and a public identifier, which enables any two participants to independently create a shared key for communicating.
A cryptosystem is pair of algorithms that take a key and convert plaintext to ciphertext and back. Plaintext is what you want to protect; ciphertext should appear to be random gibberish. The design and analysis of today's cryptographic algorithms is highly mathematical.