A biometric word list is a list of words that can be used to authentically and reliably communicate numeric information by voice. The words in the list correspond to one of each of the 256 unique byte values, and are carefully chosen for their phonetic distinctiveness. The properties of the human voice serve as the authentication mechanism. The idea was originated by Phil Zimmermann, the inventor of PGP, and Patrick Juola, a computational linguist. A word is a unit of language that carries meaning and consists of one or more morphemes which are linked more or less tightly together. ... Number is the current mathematics collaboration of the week! Please help improve it to featured article standard. ... A byte is commonly used as a unit of storage measurement in computers, regardless of the type of data being stored. ... Phonetics (from the Greek word φωνή, phone = sound/voice) is the study of sounds (voice). ... Phil Zimmermann is the creator of the popular PGP encryption software. ... Pretty Good Privacy (PGP) is a computer program which provides cryptographic privacy and authentication. ... The following is a list of linguists, those who study linguistics. ...

The first (and only?) biometric word list is one developed by Zimmermann and Juola, with the assistance of Zhahai Stewart and Grady Ward. It was developed to permit the verbal authentication of Diffie-Hellman key exchange, and of cryptographic key fingerprints. The information conveyed using a biometric word list can also be conveyed by simply reading decimal or hexadecimal numbers. However, some numbers sound similar to each other ("five" and "nine"; "B" and "D"; etc.) and can lead to errors in "transmission", so the conversion to words is used. It is similar to the use of the military alphabet for the communication of letters. Authentication is the act of establishing or confirming something or someone as authentic. ... Diffie-Hellman key exchange is a cryptographic protocol which allows two parties to agree on a secret key over an insecure communication channel. ... In cryptography, a cryptographic hash function is a hash function with certain additional security properties to make it suitable for use as a primitive in various information security applications, such as authentication and message integrity. ... The decimal (base ten or occasionally denary) numeral system has ten as its base. ... In mathematics and computer science, hexadecimal, or simply hex, is a numeral system with a radix or base of 16 usually written using the symbols 0–9 and A–F or a–f. ... FAA radiotelephony phonetic alphabet and Morse code chart. ...

The Zimmermann/Juola list is actually composed of two parallel lists, one of two-syllable words, the other of three-syllable words. To compose the verbal equivalent of a numeric value, the two lists are used in an alternating manner; the first byte is represented by the appropriate word in the two-syllable list; the next byte by the appropriate word in the three-syllable list; etc. This serves as an error detection mechanism, to address the tendency of people to transpose consecutive words, duplicate words, and omit words when reading aloud lists of random words.

An example of words from the parallel lists are as follows:

Thus, the randomly chosen sixteen-digit decimal number 9052743058066898, equivalent to the fourteen-digit hexadecimal number 20 29 6B FE 38 0D D2 (with spaces added for clarity of demonstration) is represented by the seven-word sequence, "bison certify glitter yesteryear classic asteroid standard", as shown by the boldfaced words in the table.

External links

• PGP User's Guide (pdf 2.13MB)