otp man page
otp — manages one-time passwords
The otp program initializes and updates your current series of one-time passwords (OTPs).
Use this to set a new series of one-time passwords. Only perform this on the console or over an encrypted link as you will have to supply your pass-phrase. The other two parameters are sequence-number and seed.
To delete a one-time password.
Choose a different algorithm from the default md5. Pick any of: md4, md5, and sha.
For getting a help message.
List the current table of one-time passwords.
To open (unlock) the otp-entry for a user.
To renew a one-time password series. This operation can be performed over an potentially eavesdropped link because you do not supply the pass-phrase. First you need to supply the current one-time password and then the new one corresponding to the supplied sequence-number and seed.
To choose a different user to set one-time passwords for. This only works when running otp as root.