Website fingerprinting (WF) is a traffic analysis attack that allows an eavesdropper to determine the web activity of a client, even if the client is using privacy technologies such as proxies, VPNs, or Tor. Recent work has highlighted the threat of website fingerprinting to privacy-sensitive web users. Many previously designed defenses against website fingerprinting have been broken by newer a...

Using a random deal of cards to players and a computationally unlimited eavesdropper, all players wish to share a common one-bit secret key which is information-theoretically secure from the eavesdropper. This can be done by the so-called key set protocol. In this paper we give a necessary and sufficient condition for a key set protocol to be “optimal,” that is, to succeed always in sharing a o...

Using polarization-entangled photons from spontaneous parametric down-conversion, we have implemented Ekert's quantum cryptography protocol. The near-perfect correlations of the photons allow the sharing of a secret key between two parties. The presence of an eavesdropper is continually checked by measuring Bell's inequalities. We investigated several possible eavesdropper strategies, including...

This paper describes how the communicating parties can employ intensity and state estimation to detect if the eavesdropper has siphoned off and injected photons in the received communication. This is of relevance in quantum cryptography based on random rotations of photon polarizations. Introduction The paper investigates the use of state and intensity measurements by Alice and Bob to detect th...

We study the problem of remote state estimation, in the presence of an eavesdropper. An authorized user estimates the state of a linear plant, based on the data received from a sensor, while the data may also be intercepted by the eavesdropper. To maintain confidentiality with respect to state, we introduce a novel control-theoretic definition of perfect secrecy requiring that the user’s expect...

Physical layer security has been considered as an important security approach in wireless communications to protect legitimate transmission from passive eavesdroppers. This paper investigates the physical layer security of a wireless multipleinput multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) communication system in the presence of a multiple-antenna eavesdropper. We ...

A classical one-time pad allows two parties to send private messages over a public classical channel-an eavesdropper who intercepts the communication learns nothing about the message. A quantum one-time pad is a shared quantum state which allows two parties to send private messages or private quantum states over a public quantum channel. If the eavesdropper intercepts the quantum communication ...

This paper investigates the problem of secure distributed lossless compression in the presence of arbitrarily correlated side information at an eavesdropper. This scenario consists of two encoders (referred to as Alice and Charlie) that wish to reliably transmit their respective (correlated) sources to a legitimate receiver (referred to as Bob) while satisfying some requirement on the equivocat...

In Mobile IPv6, each packet sent and received by a mobile node contains its home address. As a result, it is very easy for an eavesdropper or for a correspondent node to track the movement and usage of a mobile node. This paper proposes a simple and practical solution to this problem. The main idea is to replace the home address in the packets by a temporary mobile identifier (TMI), that is cry...

In this paper we address physical layer security in MIMO frequency selective wireless channels in the presence of a passive eavesdropper, i.e., the associated channel is unknown to the transmitter. Signalling is based on orthogonal frequency division multiplexing (OFDM). Spatial beamforming and artificial noise broadcasting are chosen as the strategy for secure transmission. The contribution of...