Similarly, the generalisation of the six-state protocol is called protocol using qudits and d+1 bases.
shows that the security of a protocol with qudits using two bases against intercept-resend attack is practically equal to the security of this protocol against non-coherent attack at any d (Vasiliu et al.
the security of the protocol using entangled qudits is investigated.
QSDC protocols can be divided into several types: ping-pong protocol (and its enhanced variants), protocols using block transfer of entangled qubits, protocols using single qubits and protocols using entangled qudits (Bostrom et al.
Another way of increasing the informational capacity of ping-pong protocol is using entangled states of qudits.
Security of quantum key distributions with entangled qudits, Physical Review A.
BULLOCK, Criteria for exact qudit universality, Phys.
QR decomposition, Givens rotations, plane rotations, parallel QR decomposition, quantum circuit design, qudits
A construction for qudits, with a state space of dimension dP (d > 2) instead of 2P, is given in [3, 2].