In general, in one aspect, an add-in card includes inaccessible memory to store an identity key, wherein the identity key is to enable a secure communication link. The add-in card also includes an isolated execution environment and a machine-accessible medium comprising content. The content when executed by the isolated execution environment causes the isolated execution environment to route secure communications between an on-line application and a remote service provider through the isolated execution environment to provide a secure communication link therebetween, detect on-line application code modifications, detect on-line application process flow modifications, and notify, via the secure communication link, the remote service provider when a modification is detected.