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Cyclic redundancy check

(also CRC)

Cyclic redundancy check definition

A cyclic redundancy check, abbreviated as CRC, is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to raw data. It involves a mathematical algorithm that calculates a unique checksum for each data block and appends it to the end. When the data block is read or transmitted, the checksum is recalculated and compared to the one appended. If the two don't match, the data has been compromised.

See also: data packet, end-to-end encryption, encrypted file transfer, parity check

Cyclic redundancy check examples

  • Data transmission: CRC is often used in networks to check the integrity of transmitted data packets.
  • Data storage: File systems and storage devices use CRC to ensure data integrity when reading and writing data.

Advantages and disadvantages of cyclic redundancy check


  • Effective error detection: CRC is particularly effective at catching burst errors, where multiple consecutive bits in the data have been corrupted.
  • Simple implementation: CRC algorithms are relatively simple and efficient, making them suitable for both hardware and software applications.


  • Limited error correction: While CRC is good at detecting errors, it doesn't have the capability to correct them.
  • Possibility of undetected errors: In rare situations, errors may remain undetected even with CRC.

Using cyclic redundancy check

  • In data transmission: Implement CRC checks at both sending and receiving ends to ensure data integrity.
  • In data storage: Use CRC as an additional layer of protection against data corruption.