Pariteettitarkastus

Pariteettitarkastus, known in English as parity check, is a simple error-detection method used in digital communication and data storage. It involves adding an extra bit, called a parity bit, to a block of data. This parity bit is set to either 0 or 1 based on the number of 1s in the original data. The goal is to make the total number of 1s in the combined data (original data plus parity bit) either always even (even parity) or always odd (odd parity).

When data is transmitted or stored, it can be corrupted by noise or errors. A parity check can detect single-bit errors. If a single bit flips during transmission or storage, the parity of the received data will be incorrect according to the established parity scheme. For example, if even parity was used and the received data block plus its parity bit now contains an odd number of 1s, an error is detected.

However, parity checks are not foolproof. They cannot detect errors where an even number of bits have flipped, as this would result in the parity remaining correct. For instance, if two bits flip in an even parity system, the total count of 1s might still be even, leading to the error going undetected. Due to its limitations, parity checks are often used in conjunction with more robust error correction codes for critical applications. Despite its simplicity, parity checking remains a fundamental concept in understanding data integrity.