Key Generation Using External Source Excitation: Capacity, Reliability, and Secrecy Exponent

Details Key Generation Using External Source Excitation: Capacity, Reliability, and Secrecy Exponent Key Generation Using External Source Excitation: Capacity, Reliability, and Secrecy Exponent

2011-10-28

arxiv.org/abs/1110.6476v1

Computer Science

Information Theory

accepted for publication, IEEE Transactions on Information Theory

Scientific paper

We study the fundamental limits to secret key generation from an excited distributed source (EDS). In an EDS a pair of terminals observe dependent sources of randomness excited by a pre-arranged signal. We first determine the secret key capacity for such systems with one-way public messaging. We then characterize a tradeoff between the secret key rate and exponential bounds on the probability of key agreement failure and on the secrecy of the key generated. We find that there is a fundamental tradeoff between reliability and secrecy. We then explore this framework within the context of reciprocal wireless channels. In this setting, the users transmit pre-arranged excitation signals to each other. When the fading is Rayleigh, the observations of the users are jointly Gaussian sources. We show that an on-off excitation signal with an SNR-dependent duty cycle achieves the secret key capacity of this system. Furthermore, we characterize a fundamental metric -- minimum energy per key bit for reliable key generation -- and show that in contrast to conventional AWGN channels, there is a non-zero threshold SNR that achieves the minimum energy per key bit. The capacity achieving on-off excitation signal achieves the minimum energy per key bit at any SNR below the threshold. Finally, we build off our error exponent results to investigate the energy required to generate a key using a finite block length. Again we find that on-off excitation signals yield an improvement when compared to constant excitation signals. In addition to Rayleigh fading, we analyze the performance of a system based on binary channel phase quantization.

Affiliated with

Also associated with

No associations

Rating

Key Generation Using External Source Excitation: Capacity, Reliability, and Secrecy Exponent does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Key Generation Using External Source Excitation: Capacity, Reliability, and Secrecy Exponent, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Key Generation Using External Source Excitation: Capacity, Reliability, and Secrecy Exponent will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-200053