What is a One-Time Password (OTP)? A One-Time Password (OTP) is
a password valid only for a single use and, once used, cannot be
used again for authentication. A Yubico OTP is unique sequence
of characters generated every time the YubiKey button is
touched. The Yubico OTP is comprised of a sequence of 32 Modhex
characters representing information encrypted with a 128 bit
AES-128 key. The information that makes up a Yubico OTP consists
of: - The Private identity of the YubiKey - Counter fields
tracking how often the YubiKey has been used - A Timer field
tracking the time between generating each OTP - A Random number
to add additional security to the encryption - A closing CRC16
checksum of all the fields Posted in: 1. The Basics