A taggant is any chemical or physical marker added to materials to allow various forms of testing. Physical taggants can take many different forms but are typically microscopic in size, included at low levels, and simple to detect. They can be utilized to differentiate authentic product from counterfeits, provide identifying information for traceability purposes (e.g. lot number, company name), determine mixing homogeneity and cross-contamination, and to detect dilution of proprietary products. Taggants are known to be widely used in the animal feed industry, plastics, inks, sheet and flexible explosives, and pharmaceuticals. An RF taggant is a radio frequency microchip used in automated identification and data capture (see RFID). In such cases, electronic devices use radio waves to track and identify items, such as pharmaceutical products, by assigning individual serial numbers to the containers holding each product. This technology may prevent the diversion or counterfeiting of drugs by allowing wholesalers and pharmacists to determine the identity and dosage of individual products. A software taggant is a cryptographic signature added to software that enables positive origin identification and integrity of programs. Software taggants use standard PKI techniques (see public key infrastructure) and were introduced by the Industry Connections Security Group of IEEE in an attempt to control proliferation of malware obfuscation via executable compression. History of taggants The word 'taggant' originates from the trademarked name "Microtaggant Identification Particles". Microtaggants were originally developed by 3M for the post detonation of explosives. In 1985, Microtrace, LLC acquired the technology and began to utilize Microtaggants for anti-counterfeiting and brand protection. Since 1985, the word 'taggant' has become widely utilized and refers to multiple variations. Explosive taggants There are two types of taggant which have been considered for use with explosives. One is to help detect the presence of a bomb in, for example, airport screening of luggage; and the other to assist the police in identifying the explosive after the detonation of such a bomb. Detection taggants These are volatile chemicals which will slowly evaporate from the explosive and can be detected in the atmosphere by either detection dogs or specialised machines. They are intended to enhance the detectability of the explosive by instruments or animals thus revealing the presence of a bomb containing the explosive to be detected. Although various technologies exist to detect untagged explosives, detection taggants help to increase their reliability. The inclusion of detection taggants in explosives is mandatory in some