Hash Type Identifier

Introduction:

Cryptographic hash functions transform arbitrary-size data into a deterministic, fixed-length digest that appears random and cannot feasibly be reversed. Because every algorithm—MD5, SHA-1, SHA-256, bcrypt, and many more—produces a distinct output length or structural pattern, hashes underpin data-integrity verification, password storage, and digital-forensics chain-of-custody workflows across industry and academia worldwide today.

This identifier scans every digest you paste or upload, measures its character count, analyses allowed symbols, and checks known prefix signatures. A lightweight reactive engine then matches those traits against a curated catalogue of algorithms, returning a ranked list of candidates per line instantly on the same page, entirely offline.

For example, when investigating a leaked credential dump, you can quickly determine whether the vendor used MD5, SHA-1, or a modern memory-hard scheme before selecting an appropriate cracking, migration, or mitigation strategy. This accelerates incident-response timelines and reduces guesswork during forensic triage. Always corroborate the suggestion with context such as salting policies or storage metadata.

Technical Details:

Concept Overview

Hash-type detection rests on observable invariants. Each cryptographic algorithm emits a digest whose length, allowed alphabet, and sometimes a version prefix remain constant whatever the input. Evaluating these invariants lets you classify the algorithm without owning the plaintext or performing the hash operation. The method is deterministic, computationally negligible, and suitable for air-gapped or low-power devices. Pattern rules such as length-32 hexadecimal, 60-character bcrypt with “$2b$”, or 22-symbol Base64 strings map directly onto MD5, bcrypt, and Base64-MD5, enabling instant classification.

Core Process

1. Receive trimmed hash string h.
2. Measure length L = |h|.
3. Determine alphabet class C (hexadecimal, Base64, modular-crypt).
4. Inspect fixed prefixes or suffixes such as “$2b$”.
5. Return all algorithms whose rule ⟨L,C,prefix⟩ matches.

Interpretation Table

Algorithms sharing length but differing in prefix or allowed symbols still resolve unambiguously. When no pattern matches, the digest is labelled “Unknown”.

Variables & Parameters

• hash – mandatory string representing the digest under inspection.
• patterns – internal catalogue of ⟨regex, name⟩ pairs.
• candidates – list of algorithms whose pattern matches hash.
• alphabet – derived character set (hexadecimal, Base64, multi-symbol).

Worked Example

Assumptions & Limitations

• Digest text is copied accurately without hidden whitespace important.
• Patterns target mainstream algorithms; proprietary schemes may escape detection.
• Collisions between algorithms with identical length rely on prefix disambiguation.
• No attempt is made to verify digest validity against source plaintext.

Edge Cases & Error Sources

• Whitespace or line-break characters embedded inside the digest.
• Base64 digests lacking “==” padding.
• Hash values truncated in log files.
• Legacy NTLM hashes using uppercase hexadecimal.

Scientific Validity & References

Pattern lengths originate from the defining specifications: RFC 1321 (MD5), FIPS 180-4 (SHA family), NIST SP 800-182 (bcrypt), and the Argon2 Internet Draft.

Privacy & Compliance

The tool processes only digest strings; no personal data or plaintext is required, aligning with GDPR’s data-minimisation principle.

Step-by-Step Guide:

Follow these simple steps to classify one or many digests.

1. Paste or type each hash into the main Hash(es) field, one per line.
2. Alternatively, upload a .txt file containing hashes.
3. Review the Top Match card for single inputs.
4. Switch between Table and JSON views to inspect structured results.
5. Copy or download the outcome as CSV or JSON for further analysis.

FAQ:

Glossary:

Digest

Fixed-length string output of a hash function.

Algorithm

Defined procedure that transforms data into a digest.

Hexadecimal

Base-16 representation using digits 0–9 and A–F.

Base64

Encoding scheme using 64 ASCII symbols, often ends with “==”.

Prefix

Static string at the start of certain digests indicating version or algorithm.