Title: PowerAlert: An Integrity Checker using Power Measurement,
Abstract: We propose PowerAlert, an efficient external integrity checker for untrusted
hosts. Current attestation systems suffer from shortcomings in requiring
complete checksum of the code segment, being static, use of timing information
sourced from the untrusted machine, or use of timing information with high
error (network round trip time). We address those shortcomings by (1) using
power measurements from the host to ensure that the checking code is executed
and (2) checking a subset of the kernel space over a long period of time. We
compare the power measurement against a learned power model of the execution of
the machine and validate that the execution was not tampered. Finally, power
diversifies the integrity checking program to prevent the attacker from
adapting. We implement a prototype of PowerAlert using Raspberry pi and
evaluate the performance of the integrity checking program generation. We model
the interaction between PowerAlert and an attacker as a game. We study the
effectiveness of the random initiation strategy in deterring the attacker. The
study shows that \power forces the attacker to trade-off stealthiness for the
risk of detection, while still maintaining an acceptable probability of
detection given the long lifespan of stealthy attacks.