title: Simple proof of security of the BB84 quantum key distribution protocol
abstract: We prove that the 1984 protocol of Bennett and Brassard (BB84) for quantum key distribution is secure. We first give a key distribution protocol based on entanglement purification, which can be proven secure using methods from Lo and Chau's proof of security for a similar protocol. We then show that the security of this protocol implies the security of BB84. The entanglement purification based protocol uses Calderbank-Shor-Steane codes, and properties of these codes are used to remove the use of quantum computation from the Lo-Chau protocol.
authors.affiliation: AT&T Labs Research, Florham Park, New Jersey 07932, USA.
authors.initials: PW
authors.lastname: Shor
authors.initials: J
authors.lastname: Preskill