2007/12/31 by Olli Ahonen, Mikko Möttönen, Mikko Mottonen +2
Computer Science · Mathematics · Physics and Astronomy · #BB84 #Combinatorics #Computer science #Computer security #Key (lock) #Mathematics #Physics #Protocol (science) #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum channel #Quantum cryptography #Quantum entanglement #Quantum information #Quantum key distribution #Quantum mechanics #Qubit #Topology (electrical circuits) #Upper and lower bounds #quant-ph
paper · pdf · doi:10.1103/physreva.78.032314
published as Physical Review A 78, 032314 (2008) · 7 pages, 5 figures, new results
openalex publication_date 2008/09/11 · arxiv created 2008/10/07 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present and analyze a quantum key distribution protocol based on sending entangled N-qubit states instead of single-qubit ones as in the trail-blazing scheme by Bennett and Brassard 1984 (BB84). Since the qubits are sent and acknowledged individually, an eavesdropper is limited to accessing them one by one. In an intercept-resend attack, this fundamental restriction allows one to make the eavesdropper's information on the transmitted key vanish if even one of the qubits is not intercepted. The implied upper bound 1∕(2N) for this information is further shown not to be the lowest, as the information can be reduced to less than 30% of that in the BB84 scheme in the case N=2. In general, the protocol is at least as secure as BB84.