Definition
Parity check is an error-detecting technique in which an extra bit (parity bit) is added to each data unit. It is a simple method of identifying errors in data transmission and storage.
How Parity Checking Works
Assume a data transfer sequence looks like this: 1010001. In this instance, there are an even number of 0s and an odd number of 1s.
If you use an even parity checking, you could add a parity bit of 1 to make the 1s even, and the transmission would look like 10100011. On the other hand, if you use an odd parity check, the transmission would look like this: 10100010.
Advantages of Parity Checking
- Simplicity: Implementing parity checks is straightforward and requires minimal resources.
- Low costs: Parity checks are cost-effective as they only add a small bit to each data block.
- Accuracy: Parity checks help ensure the communication’s accuracy by verifying every transmission.
Disadvantages of Parity Check
- Limited error detection: Two-dimensional parity checks can only identify errors that alter the parity bit.
- False errors: Parity checks can sometimes flag false positives in data transmission.
- Basic security: Although a parity check can be a great security enhancement, attackers can easily bypass it with software that retains the parity bit the same.