Iskandar Bahari

Implementation of two way Quantum Key Distribution protocol with decoy state

We report on the first demonstration of a two way Quantum Key Distribution (QKD) protocol with decoy state. The experiment was conducted over free space medium and exhibits a significant increase in the maximum secure distance of a two way QKD protocol specifically the LM05 protocol.

Decoy states and two way quantum key distribution schemes

We study the possible application of the decoy state method on a basic two way quantum key distribution (QKD) scheme to extend its distance. Noting the obvious advantage of such a QKD scheme in allowing for single as well as double photon contributions, we derive relevant lower bounds on the corresponding gains in a practical decoy state implementation using two intensities for decoy states. We work with two different approaches in this vein and compare these with an ideal infinite decoy state case as well as the simulation of the original.

Two way Quantum Key Distribution protocol with Weak+Vacuum decoy state

We consider a practical implementation of decoy state protocol with a two way Quantum Key Distribution protocol using the Weak+Vacuum decoy state scheme. The result from numerical simulation was very encouraging given that the maximum secure distance was very close to the case of maximum theoretical limit using infinite decoy state.

Weak+Vacuum and One Decoy States with Two Way Quantum Key Distribution Protocol

We present relevant bounds for the case of weak+vacuum decoy state and one decoy state for a two-way four states Quantum Key Distribution (QKD) protocol. The numerical simulation result is significant given that an improvement in maximum secure distance of nearly twice the original one is achieved.

AES: Current security and efficiency analysis of its alternatives

The Advanced Encryption Standard (AES) has been in existence over the last 11 years. It was widely accepted as the de facto standard in many security-related applications such as SSL/TLS, Microsoft BitLocker Drive Encryption, Skype and many others. Recently in 2011, the AES was claimed to be theoretically broken in the single-key attack model using a new technique called biclique. Just two years before in 2009, the AES with 192- and 256- bit keys were found to be theoretically broken in the related-key attack model. This paper reviews existing attacks on the AES and evaluates the efficiency of recent block cipher proposals as alternatives to the AES. These block ciphers were proposed to patch the AES against the related-key type of attack.

Secure communication with practical two way Quantum Key Distribution protocol and Weak+ Vacuum decoy state

A practical implementation of a two way Quantum Key Distribution protocol namely the LM05 protocol with the Weak+Vacuum decoy state protocol having the double photon gain excluded from the final secure key rate calculation is reconsidered. The numerical analysis result has shown that the performance was better than the case when single and double photon gain was lumped.

Erroneous signal detection and secure distance improvement in two way Quantum Key Distribution protocol with decoy state

The erroneous signal detection characterizes the quality of alignment and stability of a Quantum Key Distribution (QKD) system. Its effect against the improvement to the maximum secure distance achievable with weak+vacuum decoy state and a two way Quantum Key Distribution protocol, namely the LM05 protocol is investigated. The result from our numerical simulation suggested that the secure distance improvement for the two key rate formulas are stable only when erroneous signal detection is at below 5%. Interestingly, at beyond 5 %, the two secure key rate formulas exhibit opposite result with one tends to increase while the other tends to decrease.

Independent attacks in imperfect settings: A case for a two-way quantum key distribution scheme

We review the study on a two-way quantum key distribution protocol given imperfect settings through a simple analysis of a toy model and show that it can outperform a BB84 setup. We provide the sufficient condition for this as a ratio of optimal intensities for the protocols.