Custom CRC Calculator

Calculate a custom 8- through 64-bit CRC by setting its width, polynomial, initial register, reflection flags, and final XOR value.

Description

Calculate Custom CRC over UTF-8 text and display the result as uppercase hexadecimal.

Custom CRC Calculator is intended for interoperability and accidental-error detection. A CRC profile is completely defined by its register width, generator polynomial, initial value, input/output reflection rules, and final XOR. This tool exposes those parameters for 8- through 64-bit profiles.1

When to use Custom CRC Calculator

Use this checksum only when a file format, device, protocol, or published test vector specifies the same named profile and parameters. Profiles with the same width can still produce unrelated results.

How Custom CRC Calculator works

A CRC profile is completely defined by its register width, generator polynomial, initial value, input/output reflection rules, and final XOR. This tool exposes those parameters for 8- through 64-bit profiles.1

How the Custom CRC function processes input

  1. Encode the entered text as UTF-8 bytes.
  2. Process the bytes with the selected algorithm and its exact parameters.
  3. Render the result in the canonical textual form shown by the tool.

Limitations and assumptions

  • Checksums are not collision-resistant and must not be used as digital signatures or security proofs.
  • Text is encoded as UTF-8; a checksum over a file's raw bytes can differ.
  • Every CRC parameter—including reflection and initialization—must match the other implementation.

Alternative or Complementary approaches

Use a cryptographic hash such as SHA-256 when malicious modification is in scope. Use the custom CRC calculator when a documented profile is not available as a preset.

References

  1. Catalogue of parametrised CRC algorithms — CRC RevEng

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