Skey OTP Calculator for Palm Pilot. The UI of this application runs on Palm Pilot, all crypto operations are performed by smartcard.
In the current version, only one combination of password/seed are cached; the only supported card is Schlumberger's Cyberflex Access; crypto operations are restricted to SHA1.
S/key is a procedure for using one time passwords (OTP's) to authenticate access to computer systems.
Skey OTP Calculator is an application that generates OTP's. It runs on Palm OS platform
and uses smartcard assistance for the cyptographic calculations.
This procedure involves no information caching and its performance is described in the table below. Generally, it's a straight line with slope of .6.
Assuming that the user would be continually using OTP Calculator, a caching mechanism has been added to the process.
Knowing that the next challenge number the user would be prompted with is ("current number" - 1), additions
have been made to step 3 of password caculation. Now, the resulting hash of "number-1" calculations is saved on the
card in "pw" file. When a user calls the card withought changing secret password and host name, the card checks
for cached data. If new OTP has been saved, it's returned immediately, and the response time becomes constant: 3 sec.
After that, the card performs calculation of the next OTP and caches it.
As a result:
To use Password Calculator you must run SK applet (SK.bin) on your smartcard and pswd_calculator (pswd_calculator.prc)
on your Palm Pilot.
When the prompt "Password saved" appears on the Palm Pilot's screen, you may erase it from the screen
(by pressing "Clear" button or erasing it manually).
The new OTP will appear in "Reply" and "Hex" fields.
Send them to email@example.com.