CAPEC Definitions / CAPEC-112
CAPEC-112: Brute Force
In this attack, some asset (information, functionality, identity, etc.) is protected by a finite secret value. The attacker attempts to gain access to this asset by using trial-and-error to exhaustively explore all the possible secret values in the hope of finding the secret (or a value that is functionally equivalent) that will unlock the asset.
Extended Description
Examples of secrets can include, but are not limited to, passwords, encryption keys, database lookup keys, and initial values to one-way functions. The key factor in this attack is the attackers' ability to explore the possible secret space rapidly. This, in turn, is a function of the size of the secret space and the computational power the attacker is able to bring to bear on the problem. If the attacker has modest resources and the secret space is large, the challenge facing the attacker is intractable. Assuming a finite secret space, a brute force attack will eventually succeed. The defender must rely on making sure that the time and resources necessary to do so will exceed the value of the information.
Mitigations
Select a provably large secret space for selection of the secret. Provably large means that the procedure by which the secret is selected does not have artifacts that significantly reduce the size of the total secret space.
Use a secret space that is well known and with no known patterns that may reduce functional size.
Do not provide the means for an attacker to determine success independently. This forces the attacker to check their guesses against an external authority, which can slow the attack and warn the defender. This mitigation may not be possible if testing material must appear externally, such as with a transmitted cryptotext.
Relationships with other CAPECs
No related CAPECs found.
Prerequisites
The attacker must be able to determine when they have successfully guessed the secret. As such, one-time pads are immune to this type of attack since there is no way to determine when a guess is correct.
