% Sender: create an even-parity word
data = [1 0 1 1 0 0 1 0];
parityBit = mod(sum(data), 2);
sent = [data parityBit];

% Channel: flip selected bits
flipPositions = [3 5];
received = sent;
received(flipPositions) = 1 - received(flipPositions);

% Receiver: check parity
errorDetected = mod(sum(received), 2) ~= 0