A user must do between 70-80 trials to train a system to recognize a signature. A lower figure is used for touch typists. The mechanism for determining timing is not for general purpose typing, only particular strings. This also brings up the fact that some times you don't always log in on the first try. Garcia is speaking to various Government agencies and computer manufacturers about this system, but it would not be appropriate to say whom.
Signatures tend to be keyboard specific, so trials are required for different keyboards.
Despite these draw backs, the system appears quite nice. There is probably be a demostration of the system at the next Compcon in San Francisco. In NASA's case, we have the spectacle of NASA management ignoring engineering concerns because of the pressure to launch. At least the NRC seems to think so, since a management reshuffle was one of their conditions for relicensing the TVA reactors. Used car salesmen and realtors sometimes exhibit deliberate dumbness when they discourage the owner from telling them about defects in a property or automobile.