paritetarkastus

Paritetarkastus, often translated as parity check or parity audit, is a process used in various fields, particularly in computing and telecommunications, to ensure the integrity and accuracy of data. The core principle involves adding an extra bit, known as a parity bit, to a binary data stream. This parity bit is set to either 0 or 1 based on a predefined rule, most commonly to make the total number of '1' bits in the group either even or odd.

In even parity, the parity bit is set so that the total count of '1's, including the parity bit itself, is an even number. For example, if a data byte has three '1's, the parity bit would be set to '1' to make the total count four (even). If the data byte had two '1's, the parity bit would be '0'. In odd parity, the parity bit is set to ensure the total count of '1's is odd.

During transmission or storage, if an error occurs, such as a bit flipping from 0 to 1 or vice versa, the parity of the data group will change. The receiving system or the system reading the data can then recalculate the parity. If the calculated parity does not match the received parity bit, an error is detected. This method is simple and effective for detecting single-bit errors. However, it cannot detect errors where an even number of bits have flipped, as the parity would remain correct. Parity checks are a fundamental but basic form of error detection.