An attacker extracts the initial bytes from an encrypted file container and uses a tool...

CEH identifies brute-force cryptanalysis as a method in which an attacker systematically tests every possible key, password, or passphrase until the correct one is found. When an attacker obtains initial bytes from an encrypted container—often referred to as known plaintext—they can use this to validate attempts as the tool iterates through candidate keys. Automated brute-force tools compare decrypted results with known header patterns, file signatures, or expected byte structures to determine when the correct key is reached. This process aligns precisely with brute-force password testing described in CEH cryptography modules. Quantum solving is not part of CEH scope, digest comparison relates to collision attacks, and analyzing output length pertains to padding oracle detection. The correct classification is automated brute-force cryptanalysis.