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KMAC128 Generator - Keccak Message Authentication Code

Generate KMAC128 authentication tags - Keccak-based MAC with 128-bit security per NIST SP 800-185.

kmac128.workspace
3 options
0 bytes UTF-8, Hex, or Base64 input
Options
Key *

0 bytes

Secure client-side computation. No data leaves your browser. Privacy Security

Result Output

What Is KMAC128?

KMAC128 is a Keccak-based Message Authentication Code defined in NIST SP 800-185, providing 128-bit security with variable-length output and optional personalization, offering an alternative to HMAC with built-in XOF capabilities.

Specifications

Output Size Variable
Standard NIST SP 800-185
Standard Year 2016
Origin Keccak submission to NIST SHA-3 competition
Origin Year 2008

Use Cases

  • NIST-compliant message authentication
  • Keccak-based MAC requirements
  • Variable-length authentication tags
  • Domain-separated MAC construction
  • SHA-3 ecosystem authentication
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Security Notice

KMAC128 is a keyed message authentication tool. Keep keys secret, use protocol-appropriate key sizes, and do not treat the output as encryption.

Related Tools

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Utilities

File Hash Verifier Verify local files against published checksums. Hash Compare Compare expected and actual digest values. Multi Hash Generator Generate common hashes from one input.

Guides

Algorithm Comparison Guide Choose the right primitive for each task. Hash Test Vectors Compare known outputs across common algorithms.

Implementation Notes

Practical usage details for this browser-based KMAC128 tool.

How to Generate a KMAC128 authentication code

  1. Choose UTF-8, Hex, Base64 input mode.
  2. Enter the text or encoded bytes you want to process.
  3. Adjust the KMAC128 options if your use case requires non-default settings.
  4. Click Generate KMAC128 Authentication Code and copy the result.

Example Input

Sample input:

abc

Use this sample input, then copy the generated authentication code from the result panel.

When Not to Use KMAC128

  • Do not use a plain hash or derivation output directly as password storage without the right password-hashing construction and parameters.
  • Do not use it as a general-purpose unkeyed hash.

Recommended Alternatives

Review related tools when you need a different output size, security margin, or keyed construction.

Frequently Asked Questions