Documentation

This tool performs local CAST5 (CAST-128) encryption/decryption with multiple modes and formats, useful for legacy protocol compatibility and data workflows.

CAST5 supports variable key lengths from 40 to 128 bits and has been extensively analyzed with no known effective attacks against the full CAST5.

Key Features

  • CAST5 support (40-128-bit keys)
  • CBC, ECB, CFB, OFB, CTR, and RAW modes
  • Multiple input/output formats and paddings
  • Key and IV validation hints

Steps

  1. Select encrypt or decrypt mode.
  2. Configure cipher mode, padding, and key settings.
  3. Enter key, IV, and text content.
  4. Process and copy output.

Notes

  • CAST5 uses 64-bit blocks and is typically not first choice for new long-term systems.
  • Keep mode, padding, and encoding identical for interoperability.
  • Avoid weak keys and insecure configurations.