Chapter 14. Cyclic Redundancy Check

14–1 Introduction

The cyclic redundancy check, or CRC, is a technique for detecting errors in digital data, but not for making corrections when errors are detected. It is used primarily in data transmission. In the CRC method, a certain number of check bits, often called a checksum, or a hash code, are appended to the message being transmitted. The receiver can determine whether or not the check bits agree with the data to ascertain with a certain degree of probability that an error occurred in transmission. If an error occurred, the receiver sends a “negative acknowledgment” (NAK) back to the sender, requesting that the message be retransmitted.

The technique is also sometimes applied to data storage devices, ...

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