Security Against Eavesdropping in Quantum Cryptography

Anindita Banerjee

Sayantan Gupta, Kartik Sau, Jyotirmoy Pramanick +3 more

In this paper, we proposed the Implementation of Perfect Time Eavesdropping in Position Based Quantum Cryptography. The Security of Quantum Key Distribution lies in the Laws of Quantum Mechanics and is recognized to be one of the most secure cryptography ever known. The major advantage of Position-Based Key Distribution is that an authenticated server or device will be able to use its InterSpace Positions while authenticating in an environment while exchanging a secure key for communication over the network. In Position Cryptography the Authentication is done by verifying that a particular Device holds a definite and fixed position in Space-Time. In this paper, we proposed the experimental Time-Based Attack which evolved as modern day Decoy-Fake Shift Attack. The key idea is: an Attacker Eve can change the Shift of the Key randomly to T1 or T2 with the probability of shift, F and G = 1-F respectively. Also, the attacker can Authenticate and Randomize the Probability F in such a way so that it ensures the Receiver's Detection Ratio is constant i.e. 1:1. So, as a result, the two parties communicating via a secure Quantum channel will not be able to detect the Eavesdropping caused by the attacker and therefore the attacker can have an Authentication over the shared key and can, therefore, the parties will not be able to conceal its information. Thus the secure Position Quantum Cryptography can be broken by this proposed Architecture model. In this paper, we represented the Architecture Model experimentally and the Security Analysis for such an attack has been proposed.

Gilles Brassard A, Norbert Lütkenhaus, Tal Mor +1 more

Zhengjun Cao, Zhenfu Cao

Signal security aims to prevent the adversary from copying communication signals—so it is with quantum cryptography. Information security focuses on preventing the adversary from knowing plaintext or cheating users—so it is with classical cryptography. Communication reliability means that the intended receiver can recover the right communication signals sent by the sender. In this note, we stress that in the presence of an adversary quantum cryptography can do nothing except for detecting the presence, because the intrusion of adversary has to disturb communication signals so that the intended receiver can not recover the right signals. But classical cryptography works well in the presence of eavesdropping although it cannot detect it. We also remark that in the past decades the functionality of quantum cryptography to detect eavesdropping has been overstated. The plan to build a large quantum photonic network is infeasible.

Andreas Poppe

Dagmar Bruß, Chiara Macchiavello

We study optimal eavesdropping in quantum cryptography with three-dimensional systems, and show that this scheme is more secure against symmetric attacks than protocols using two-dimensional states. We generalize the according eavesdropping transformation to arbitrary dimensions, and discuss the connection with optimal quantum cloning.