Method of authenticating and/or tamper-detecting using a nucleic acid tag

A method for authentication of, or detecting tampering with, an item of interestusing a nucleic acidis disclosed. The method of tamper-detecting comprises: sealing within an item of interesta nucleic acidtag (340) comprised of a nucleotidesupport platform (320) attached to a nucleic acidmolecule; and examining 240 an exterior surface of the item of interestfor the presence of the nucleic acidtag, wherein the presence of the tag on the exterior surface indicates tampering. The method of authenticating an item of interestcomprises: adding to the item of interesta nucleic acidtag as recited above, wherein information about the item of interestis contained within the nucleic acidmolecule; sampling a portion of an item for the presence of the nucleic acidtag, detecting the presence of the nucleic acidtag in the sample, wherein the presence of the nucleic acidtag authenticates the item. The nucleic acidmolecule could be composed of nucleotidessuch as ribonucleotides, deoxyribonucleotides, and nucleotideanalogues. The nucleic acidmolecule could be an oligonucleotide. The tamper-detecting method could also involve coding information about the item of interestwithin the nucleic acidmolecule. The nucleotidesupport could be a nanoparticle or other solid support.