The work described in this paper investigates the problem
of identifying and deterring stealthy malicious processes on
a host. We point out the lack of strong application iden-
tication in main stream operating systems. We solve the
application identication problem by proposing a novel iden-
tication model in which user-level applications are required
to present identication proofs at run time to be authenti-
cated by the kernel using an embedded secret key. The se-
cret key of an application is registered with a trusted kernel
using a key registrar and is used to uniquely authenticate
and authorize the application. We present a protocol for
secure authentication of applications. Additionally, we de-
velop a system call monitoring architecture that uses our
model to verify the identity of applications when making
critical system calls. Our system call monitoring can be
integrated with existing policy specication frameworks to
enforce application-level access rights. We implement and
evaluate a prototype of our monitoring architecture in Linux
as device drivers with nearly no modication of the ker-
nel. The results from our extensive performance evaluation
shows that our prototype incurs low overhead, indicating the
feasibility of our model
