1. A processor configured to validate code during runtime, comprising: an instruction pipeline configured to decode and execute instructions along a control flow path of a block; a signature generator configured to generate a signature of at least one of: a trace cache storing a plurality of blocks, the control flow path of the block, and the instructions to be executed along the control flow path of the block, concurrently with decoding of the respective instructions on the pipeline; a signature cache configured to securely receive and store a set of valid signatures, including a signature associated with a content of the instruction pipeline or trace cache; and a validator configured to validate the generated signature against a signature from the signature cache.