Networking / Beginners

# Keyspace

The keyspace is related to the key used for encryption and decryption. The keyspace refers to the range of possible values that can be used in the key. The wider the range of the keyspace, the more difficult it can be to break or compromise the encryption.

## Keystream

A keystream is a stream of random or pseudo-random data that is combined with the plain-text to produce cipher-text. Different mathematical or logic operations can be performed on the keystream in combination with the plain-text to generate the ciphertext. The keystream is not necessarily related to the key or the safeguarded information in any way.

The following logic operations can be performed on the keystream and plain-text (among others):

• Conjunction (AND)
• Disjunction (OR)
• Negation (NOT)
• Not both (NAND)
• Neither Nor (NOR)
• Exclusive OR (XOR)

Note Pseudo-random numbers are a series of numbers that are similar to random numbers but cannot be defined as being completely random, because they are generated from a relatively small set of initial values. Their scope is limited or finite.