  In this paper we consider the compressed sensing-based encryption and
proposed the conditions in which the perfect secrecy is obtained. We prove when
the Restricted Isometery Property (RIP) is hold and the number of measurements
is more than two times of sparsity level i.e. M \geq 2k, the perfect secrecy
condition introduced by Shannon is achievable if message block is not equal to
zero or we have infinite block length
