Encoders / DecodersLesson 20Free preview

CRC32 Checksum

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Summary

CRC32 calculates 32-bit checksums of data to detect unintended changes or damage. The value is quickly calculated and is often used in file formats such as ZIP and PNG. Small changes in the data usually result in very different checksums. But CRC32 is not a cryptographic function: its value can be falsified and collisions can be detected, so it's not suitable for security.

Key points

Generates a 32-bit checksum from a series of bytes
Useful for detecting data corruption during transfer or storage
A small change in the data changes the checksum value
Not a security device because it's easy to fake.
It's widely used in ZIP, PNG, and network protocols.

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