Most of today’s computers are connected to the Internet or at least to a local network, exposing system vulnerabilities to the potential attackers. One of the attackers’ goals is the execution of the unauthorized code. In this paper we propose a framework that will allow execution of the trusted code only and prevent malicious code from executing. The proposed framework relies on the runtime verification of basic block signatures. The basic block signatures are generated during a trusted installation process, using a signature function with secret coefficients and the address of the basic block within a program. The result of the trusted installation is the encrypted basic block signature table (BBST), which is appended to the program binary. The potential of the proposed framework is evaluated using traces of SPEC CPU2000 benchmarks. The results indicate that the proposed mechanism does not have a large negative impact on performance. Keywords Computer security, trusted execution...