On confidentiality-preserving real-time locking protocols

Coordinating access to shared resources is a challenging task, in particular if real-time and security aspects have to be integrated into the same system. However, rather than exacerbating the problem, we found that considering real-time guarantees actually simplifies the security problem of preventing information leakage over shared-resource covert channels. We introduce a transformation for standard real-time resource locking protocols and show that protocols transformed in this way preserve the confidentiality guarantees of the schedulers on which they are based. Through this transformation, we were able to prove that four out of the seven investigated protocols are information-flow secure.