What process appends redundant check symbols to a message for error detection?

The process that appends redundant check symbols to a message for error detection is encoding. Encoding is a technique used to transform data into a particular format for efficient transmission or storage, while also adding additional information that can help detect errors during communication.

In the context of error detection, redundancy is crucial. By appending check symbols, which are often derived from the content of the message itself, the system can identify when the data has been altered during transmission. For instance, methods like checksums or cyclic redundancy checks (CRC) are types of encoding that generate additional bits that represent the original data, allowing the receiver to verify the integrity of the message.

Other processes such as encryption focus on securing data from unauthorized access rather than ensuring its integrity. Decoding is the reverse process of encoding; it retrieves the original data from its encoded form without focusing on error detection. Compression, on the other hand, is aimed at reducing the size of the data for storage or transmission efficiency, rather than adding symbols for error-checking purposes.