Embodiments of the invention provide a method a authenticating a transaction at the point of transaction. In some embodiments of the invention, a unique signature is created based at least in part on a hardware profile of the system. In some embodiments, a request is received from a user to perform a transaction using the system. In some embodiments, in response to receiving the request the system may determine whether malware has compromised the signature creation algorithm, and if so, prevent the signature creation algorithm from creating a key based on the unique signature. Alternatively, if not, the system may allow the signature creation algorithm to create a key based on the unique signature.