CRC-64

CRC-64

CRC-64 (64-bit Cyclic Redundancy Check), is an algorithm that produces a 64-bit checksum from a block of data.

It is mainly used to detect accidental data changes caused by:

• File corruption
• Storage errors
• Network transmission errors
• Incomplete or damaged data

CRC-64 checksum can be calculated before storing or sending a file. After the file is retrieved, the checksum is calculated again. If the two values are different, the data was probably modified or corrupted. That's why we often see this checksum when installing applications to make sure we don't have corrupt files.

WARNING: CRC-64 is designed for error detection. It is not a cryptographic hash and should not be used for passwords, signatures, or security verification.

CRC-64 variants in this tool:

• xz

  • The default option.
  • Uses a reflected version of the ECMA polynomial.
  • Commonly used by XZ compressed files.
  • Compatible with Go's crc64.ECMA implementation.

• ecma-182

  • The original, unreflected CRC-64 defined by the ECMA-182 standard.
  • Used for standardized data-integrity checks.

• go-iso

  • Uses Go's CRC-64 ISO polynomial.
  • Select this when compatibility with Go's crc64.ISO implementation is required.

• ms

  • A Microsoft-specific CRC-64 variant.
  • Used by some Microsoft and Windows data formats.

• nvme

  • A CRC-64 variant defined for NVMe storage.
  • Used to detect data corruption in NVMe storage devices.

• redis

  • The CRC-64 variant used by Redis.
  • Used for compatibility with Redis data and checksum operations.

• we

  • An unreflected ECMA-based variant.
  • Uses different initial and final values from ecma-182.
  • Used for compatibility with systems that require CRC-64/WE.

Choosing a variant

Use the variant required by the file format, protocol, library, or system you are working with.

When there is no compatibility requirement, use the default:

xz

Checksums generated by different variants will usually not match, even when calculated from the same data.