Remote Attestation on Legacy Operating Systems With Trusted Platform Modules

A lot of progress has been made to secure network communication, e.g., through the use of cryptographic algorithms. However, this offers only a partial solution as long as the communicating end points still suffer from security problems. A number of applications require remote verification of software executing on an untrusted platform. Trusted computing solutions propose to solve this problem through software and hardware changes, typically a secure operating system and the addition of a secure coprocessor respectively. On the other hand, timed execution of code checksum calculations aims for a solution on legacy platforms, but can not provide strong security assurance. We present a mixed solution by using the trusted computing hardware, namely the time stamping functionality of the trusted platform module, in combination with a timing based remote code integrity verification mechanism. In this way, we do not require a secure operating system, but at the same time the overall security of the timed execution scheme can be improved.