| Name |
Encryption Brute Forcing |
|
| Likelyhood of attack |
Typical severity |
| Low |
Low |
|
| Summary |
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. |
| Prerequisites |
Ciphertext is known. Encryption algorithm and key size are known. |
| Execution Flow |
| Step |
Phase |
Description |
Techniques |
| 1 |
Explore |
Determine the ciphertext and the encryption algorithm. |
|
| 2 |
Experiment |
Perform an exhaustive brute force search of the key space, producing candidate plaintexts and observing if they make sense. |
|
|
| Solutions | 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 |
|
CWE ID
|
Description
|
| CWE-326 |
Inadequate Encryption Strength |
| CWE-327 |
Use of a Broken or Risky Cryptographic Algorithm |
| CWE-693 |
Protection Mechanism Failure |
| CWE-1204 |
Generation of Weak Initialization Vector (IV) |
|
| Related CAPECS |
|
CAPEC ID
|
Description
|
| CAPEC-112 |
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. |
| CAPEC-668 |
An adversary can exploit a flaw in Bluetooth key negotiation allowing them to decrypt information sent between two devices communicating via Bluetooth. The adversary uses an Adversary in the Middle setup to modify packets sent between the two devices during the authentication process, specifically the entropy bits. Knowledge of the number of entropy bits will allow the attacker to easily decrypt information passing over the line of communication. |
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