  The paper presents the implementation of a quantum cryptography protocol for
secure communication between servers in the cloud. As computing power
increases, classical cryptography and key management schemes based on
computational complexity become increasingly susceptible to brute force and
cryptanalytic attacks. Current implementations of quantum cryptography are
based on the BB84 protocol, which is susceptible to siphoning attacks on the
multiple photons emitted by practical laser sources. The three-stage protocol,
whose implementation is described in this paper, is a departure from
conventional practice and it obviates some of the known vulnerabilities of the
current implementations of quantum cryptography. This paper presents an
implementation of the three-stage quantum communication protocol in free-space.
To the best of the authors' knowledge, this is the first implementation of a
quantum protocol where multiple photons can be used for secure communication.
