Techniques for use of carbon nanotubes as an anti-tampering feature and for use of randomly metallic or semiconducting carbon nanotubes in the generation of a physically unclonable cryptographic key generation are provided. In one aspect, a cryptographic key having an anti-tampering feature is provided which includes: an array of memory bits oriented along at least one bit line and at least one word line, wherein each of the memory bits comprises a memory cell, wherein the cryptographic key is stored in the memory cell, and wherein the memory cell is connected to the at least one bit line; and a metallic carbon nanotube interconnect which connects the memory cell to the at least one word line. A cryptographic key and method for processing the cryptographic key are also provided.