MITRE ATT&CK / Techniques / T1600.001

Weaken Encryption: Reduce Key Space

ID
T1600.001
Tactics
TA0112 Defense Impairment
Sub-technique of
T1600 Weaken Encryption
Platforms
Network Devices
Data sources
File Modification, Command Execution, Network Traffic Content
Source
attack.mitre.org
MITRE last modified
12 May 2026

Adversaries may reduce the level of effort required to decrypt data transmitted over the network by reducing the cipher strength of encrypted communications.[1]

Adversaries can weaken the encryption software on a compromised network device by reducing the key size used by the software to convert plaintext to ciphertext (e.g., from hundreds or thousands of bytes to just a couple of bytes). As a result, adversaries dramatically reduce the amount of effort needed to decrypt the protected information without the key.

Adversaries may modify the key size used and other encryption parameters using specialized commands in a Network Device CLI introduced to the system through Modify System Image to change the configuration of the device. [2]

Detection

References

  1. Cisco Synful Knock Evolution
  2. Cisco Blog Legacy Device Attacks