Patent ID: 7305559

Claim:
A computer readable medium bearing logic executable by a computer for: receiving, from a user, a unique identifier, the unique identifier comprising both a sequence of keystrokes and inter-keystroke intervals associated with provision of those keystrokes; comparing the unique identifier received from the user with a reference unique identifier by: comparing the sequence with a sequence from the reference unique identifier to render a sequence comparison; comparing at least one absolute inter-keystroke interval of the unique identifier with a respective absolute inter-keystroke interval of the reference unique identifier to render an absolute comparison and returning a true indication if the absolute inter-keystroke interval of the unique identifier is within a predetermined tolerance of the absolute inter-keystroke interval of the reference identifier; comparing at least one relative inter-keystroke interval of the unique identifier, the relative inter-keystroke interval being a ratio of an absolute inter-keystroke interval in the unique identifier to a predetermined absolute inter-keystroke interval in the unique identifier, with a respective reference relative inter-keystroke interval of the reference unique identifier, the reference relative inter-keystroke interval being a ratio of an absolute inter-keystroke interval in the reference unique identifier to a predetermined absolute inter-keystroke interval in the reference unique identifier, to render a relative comparison and returning a true indication if the relative inter-keystroke interval of the unique identifier is within a predetermined tolerance of the relative inter-keystroke interval of the reference identifier; and authenticating said user if the sequence comparison, the absolute comparison, and said relative comparison all return a true indication, further comprising the step of entry by the user of the reference unique identifier, wherein said predetermined tolerance is explicitly provided by the user during said step of entry by the user of the reference unique identifier.