CAPEC-20 Detail

An attacker, armed with the cipher text and the encryption algorithm used, performs an exhaustive (brute force) search on the key space to determine the key that decrypts the cipher text to obtain the plaintext.

Execution Flow

Determine the ciphertext and the encryption algorithm.

Perform an exhaustive brute force search of the key space, producing candidate plaintexts and observing if they make sense.

Prerequisites

Ciphertext is known.
Encryption algorithm and key size are known.

Skills Required

Brute forcing encryption does not require much skill.

Resources Required

Array

Mitigations

Use commonly accepted algorithms and recommended key sizes. The key size used will depend on how important it is to keep the data confidential and for how long.
In theory a brute force attack performing an exhaustive key space search will always succeed, so the goal is to have computational security. Moore's law needs to be taken into account that suggests that computing resources double every eighteen months.

Related Weaknesses

Submission

Modifications