A processor including instruction support for implementing hash algorithms may issue, for execution, programmer-selectable hash instructions from a defined instruction set architecture (ISA). The processor may include a cryptographic unit that may receive instructions for execution. The instructions include hash instructions defined within the ISA. In addition, the hash instructions may be executable by the cryptographic unit to implement a hash that is compliant with one or more respective hash algorithm specifications. In response to receiving a particular hash instruction defined within the ISA, the cryptographic unit may retrieve a set of input data blocks from a predetermined set of architectural registers of the processor, and generate a hash value of the set of input data blocks according to a hash algorithm that corresponds to the particular hash instruction.