 Charles H. Bennett (physicist)

Charles H. Bennett and Gilles Brassard proposed quantum key distribution using qubits prepared in two incompatible measurement bases. The sender and receiver disclose their basis choices and retain events with matching bases; they test a sample for disturbance before deriving a key. A simple intercept-and-resend attack illustrates the principle: an eavesdropper choosing a random one of the two bases chooses incorrectly half the time and then causes a wrong retained bit half the time, giving a $1/4$ error rate. This example is an attack analysis, rather than a complete security proof.^[ref]

Charles H. Bennett is an American theoretical physicist and computer scientist known for his significant contributions to the fields of quantum information theory and classical information theory. He was born on April 16, 1931. Bennett is best known for co-inventing the concept of quantum cryptography and quantum teleportation, which are foundational concepts in quantum information science.