A parity bit is an extra bit added to a byte of data to ensure even or odd parity. It helps detect errors in transmitted data and can only report odd bit errors.
A parity bit is used for error checking on an array of data. A byte is made up of eight data bits, seven which actually contain data and the parity bit. The bit helps ensure that the array is always odd or even, one or zero. It allows you to check for errors in transmitted data by allowing the receiving computer to make sure that a group of bits is even or odd when the data arrives.
When data is transmitted, the binary digits sent must match the bit length expected by the recipient. If the expected data is even and the data sent with its parity bit is odd, the receiver may reject the data due to a parity error.
A parity bit helps ensure that each data array has an even number of drives, for even parity, or an odd number of drives for odd parity. Adding the extra bit to the data packet will allow the data to be quickly checked for errors when received. The extra bit acts as an error detection code or mechanism so that unexpected data is not received.
For example, suppose a document is submitted for review and the document is contained in a data packet. The data packet with its parity bit is odd. The packet is transmitted to another computer somewhere on the internet and the remote server expects the data packet to have odd parity. When the data arrives, the host machine receives a packet with even parity. The host will reject the packet because the parity of the sent data does not match and must be in error.
If a data packet is received and it is out of parity, with the parity bit opposite to that expected by the receiving computer, the recipient will send a message indicating transmission error to the host which has not received the data as expected. Many times the original sender of the data packet will resend the transmission after recalculating the data parity which can sometimes correct the problem.
Parity bit error checking methods are far from perfect. The parity bit error checking scenario can only correctly report an odd number of bit errors. If an even number of transmitted bits have errors, the transmission will be reported as correct even if the data within the transmission is corrupted.
Protect your devices with Threat Protection by NordVPN
