Key Space (cryptography)
In cryptography, an algorithm's key space refers to the set of all possible keys that can be used to initialize it. For example, if an algorithm works using a key that is a string of 10 bits, then its key space is the set of all binary strings of length 10. i.e. we have key space of size 210 = 1024.
To avoid adversaries from guessing the key using a brute-force attack, the key space is usually designed to be extremely large. Another desirable attribute is that the key space be flat, having no or very few weak keys. If the key was selected randomly from all possible keys, on average half the key space must be searched to find the solution. However, if an attacker has some knowledge of how the key was likely selected, the search time can be far less.
Read more about Key Space (cryptography): Examples
Famous quotes containing the words key and/or space:
“This is the Key of the Kingdom:
In that Kingdom is a city;”
—Unknown. This Is the Key (l. 1–2)
“The flattering, if arbitrary, label, First Lady of the Theatre, takes its toll. The demands are great, not only in energy but eventually in dramatic focus. It is difficult, if not impossible, for a star to occupy an inch of space without bursting seams, cramping everyone else’s style and unbalancing a play. No matter how self-effacing a famous player may be, he makes an entrance as a casual neighbor and the audience interest shifts to the house next door.”
—Helen Hayes (1900–1993)