KMB09 protocol (named after Muhammad Mubashir Khan, Michael Murphy and Almut Beige) is an alternative
quantum key distribution
Quantum key distribution (QKD) is a secure communication method which implements a cryptographic protocol involving components of quantum mechanics. It enables two parties to produce a shared random secret key known only to them, which can then be ...
protocol
Protocol may refer to:
Sociology and politics
* Protocol (politics), a formal agreement between nation states
* Protocol (diplomacy), the etiquette of diplomacy and affairs of state
* Etiquette, a code of personal behavior
Science and technolog ...
, where
Alice and Bob
Alice and Bob are fictional characters commonly used as placeholders in discussions about cryptographic systems and protocols, and in other science and engineering literature where there are several participants in a thought experiment. The A ...
use two
mutually unbiased bases
In quantum information theory, mutually unbiased bases in Hilbert space C''d'' are two orthonormal bases \ and \ such that the square of the magnitude of the inner product between any basis states , e_j\rangle and , f_k\rangle equals the inverse o ...
with one of them encoding a ‘0’ and the other one encoding a ‘1’. The security of the scheme is due to a minimum index transmission error rate (ITER) and
quantum bit
In quantum computing, a qubit () or quantum bit is a basic unit of quantum information—the quantum version of the classic binary bit physically realized with a two-state device. A qubit is a two-state (or two-level) quantum-mechanical system, ...
error rate (QBER) introduced by an
eavesdropper
Eavesdropping is the act of secretly or stealthily listening to the private conversation or communications of others without their consent in order to gather information.
Etymology
The verb ''eavesdrop'' is a back-formation from the noun ''eaves ...
. The ITER increases significantly for higher-dimensional photon states. This allows for more noise in the
transmission line
In electrical engineering, a transmission line is a specialized cable or other structure designed to conduct electromagnetic waves in a contained manner. The term applies when the conductors are long enough that the wave nature of the transmis ...
, thereby increasing the possible distance between Alice and Bob without the need for intermediate nodes.
[{{Cite journal , doi=10.1088/1367-2630/11/6/063043, title=High error-rate quantum key distribution for long-distance communication, journal=New Journal of Physics, volume=11, issue=6, pages=063043, year=2009, last1=Mubashir Khan, first1=Muhammad, last2=Murphy, first2=Michael, last3=Beige, first3=Almut, bibcode=2009NJPh...11f3043M, arxiv=0901.3909]
References
Quantum cryptography
Quantum cryptography protocols