CRC-64 Checksum Calculator

What is CRC-64?

CRC-64 (Cyclic Redundancy Check) is a 64-bit error-detecting code commonly used to verify data integrity. It provides a stronger error detection capability compared to CRC-32 due to its larger bit size. The specific variation used on this page is CRC-64/ECMA-182, a widely recognized standard.

Understanding Checksums

A checksum is like a digital fingerprint of your data. When you create or download a file, its checksum is a unique value calculated from its contents. If even a single bit in the file changes, the checksum will be completely different. This makes checksums perfect for:

  • File Verification: Compare checksums to ensure a file hasn't been corrupted during download or transfer
  • Data Integrity: Quickly detect if files have been modified or tampered with
  • Error Detection: Identify errors in data transmission or storage

How CRC-64 Works

The CRC-64 algorithm treats data as a polynomial and performs binary division by another fixed polynomial (known as the "generator polynomial"). The remainder of this division becomes the CRC value.

This specific implementation uses the standard ECMA-182 polynomial: 0x42F0E1EBA9EA3693, with these parameters:

  • Width: 64 bits
  • Polynomial: 0x42F0E1EBA9EA3693
  • Initial Value: 0x0000000000000000
  • Input Reflected: False
  • Result Reflected: False
  • Final XOR Value: 0x0000000000000000

CRC-64 offers a good balance between computational complexity and collision resistance, making it suitable for verifying larger files where stronger integrity checking is needed.

Learn more on Wikipedia