Abstract:
Dynamic cache partitioning for shared Last Level
Caches (LLC) is deployed in most modern multicore systems
to achieve process isolation and fairness among the applications
and avoid security threats. Since LLC has visibility of all cache
blocks requested by several applications running on a multicore
system, a malicious application can potentially threaten the system
that can leverage the dynamic partitioning schemes applied to
the LLCs by creating a timing-based covert channel attack. We
call it as Cache Partitioned Covert Channel (CPCC) attack. The
malicious applications may contain a trojan and a spy and use
the underlying shared memory to create the attack. Through
this attack, secret pieces of information like encryption keys or
any secret information can be transmitted between the intended
parties. We have observed that CPCC can target single or multiple
cache sets to achieve a higher transmission rate with a maximum
error rate of 5% only. The paper also addresses a few defense
strategies that can avoid such cache partitioning based covert
channel attacks
