[GoD-Tony]

Originally Posted by Wikipedia A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to raw data.

CRC-32 is very fast, even on larger files, and it's designed to handle unintentional changes in data. Useful in cases such as verifying the integrity of a downloaded file.

It should not be used for security purposes.

PHP Code:

/**
 * Produces a CRC-32 checksum for a given data stream.
 *
 * @param data        Input data to calculate the checksum from.
 * @param size        Total size of data in bytes.
 * @return            CRC-32 checksum as an integer.
 */
stock CRC32_Data(const String:data[], size)

/**
 * Produces a CRC-32 checksum for a given file.
 *
 * @param path        Path to the file.
 * @return            CRC-32 checksum as an integer.
 * @error            Failed to open file or file does not exist.
 */
stock CRC32_File(const String:path[]) 


[Powerlord]

CRC-32 may be useful to tell if unintentional changes were made, but it has a much higher collision rate than newer methods such as MD5, SHA-1, and SHA-256/512 (aka SHA-2).