Eleventh Hour Security+

General Cryptography

Locks and keys have been used for centuries to keep items—and communications—hidden. In many locks in the physical world, it is possible to close the lock without having the key (or the code, for a combination lock). Other locks require a key to lock them, that key also being required to unlock them.

There are analogous mechanisms in the online world, except that the terminology is different. Locking and unlocking are not common terms in cryptography—instead, “encrypting” data turns it from readable into unreadable, and “decrypting” data changes it from unreadable to readable. Locks are now “algorithms” or methods by which encryption is done, and keys, thankfully are still represented by the term “keys.” The two kinds of ...