Which attack breaks passphrases into fingerprints of varying lengths to crack passwords?

Which attack breaks passphrases into fingerprints of varying lengths to crack passwords?

• A. Toggle-Case Attack
• B. Combinator Attack
• C. Fingerprint Attack
• D. PRINCE Attack

Answer: (C)

Fingerprints describe how a passphrase is built from recognizable chunks and patterns rather than as a random jumble of characters. In a fingerprint attack, the attacker models a password as a sequence of segments (fingerprints) of varying lengths—like word fragments, numbers, or symbols arranged in common ways—and then tries combinations of those segments. This targets passphrases because people often construct them from multiple words or familiar fragments, sometimes with capitalization changes or appended numbers, rather than typing entirely random characters. By focusing on the structure—the fingerprints—and the plausible lengths of each piece, the attack narrows the search space and can crack multiword passphrases much more efficiently than brute-forcing every possible character string. For example, if a password is likely built from two dictionary words with a numeric suffix, the fingerprint model considers plausible segment lengths and combinations such as [word][word][digits], including variations in capitalization or minor alterations. The attack then tests candidate fingerprints and fills in actual words or fragments to match the hash. This approach is distinct from toggling case within words, purely combinatorial word assembly, or a probabilistic incremental method, which address different aspects of password construction or guessing strategies.

Fingerprints describe how a passphrase is built from recognizable chunks and patterns rather than as a random jumble of characters. In a fingerprint attack, the attacker models a password as a sequence of segments (fingerprints) of varying lengths—like word fragments, numbers, or symbols arranged in common ways—and then tries combinations of those segments. This targets passphrases because people often construct them from multiple words or familiar fragments, sometimes with capitalization changes or appended numbers, rather than typing entirely random characters. By focusing on the structure—the fingerprints—and the plausible lengths of each piece, the attack narrows the search space and can crack multiword passphrases much more efficiently than brute-forcing every possible character string.

For example, if a password is likely built from two dictionary words with a numeric suffix, the fingerprint model considers plausible segment lengths and combinations such as [word][word][digits], including variations in capitalization or minor alterations. The attack then tests candidate fingerprints and fills in actual words or fragments to match the hash. This approach is distinct from toggling case within words, purely combinatorial word assembly, or a probabilistic incremental method, which address different aspects of password construction or guessing strategies.