Quantifying Timing Leaks and Cost Optimisation
  We develop a new notion of security against timing attacks where the attacker is able to simultaneously observe the execution time of a program and the probability of the values of low variables. We then show how to measure the security of a program with respect to this notion via a computable estimate of the timing leakage and use this estimate for cost optimisation. 
Alessandra Di Pierro, Chris Hankin and Herbert Wiklicky