  The increased capabilities of modern real-time systems (RTS) expose them to
various security threats. Recently, frameworks that integrate security tasks
without perturbing the real-time tasks have been proposed, but they only target
single core systems. However, modern RTS are migrating towards multicore
platforms. This makes the problem of integrating security mechanisms more
complex, as designers now have multiple choices for where to allocate the
security tasks. In this paper we propose HYDRA, a design space exploration
algorithm that finds an allocation of security tasks for multicore RTS using
the concept of opportunistic execution. HYDRA allows security tasks to operate
with existing real-time tasks without perturbing system parameters or normal
execution patterns, while still meeting the desired monitoring frequency for
intrusion detection. Our evaluation uses a representative real-time control
system (along with synthetic task sets for a broader exploration) to illustrate
the efficacy of HYDRA.
