SKEY(1)

NAME
skey, otp-md4, otp-md5, otp-sha1, otp-rmd160 - respond to an OTP challenge

SYNOPSIS
skey [-x] [ -md4 | -md5 | -sha1 | -rmd160] [-n count] [-p passwd] <sequence#>[/] key

DESCRIPTION
S/key is a procedure for using one-time passwords to authenticate access to computer systems. It uses 64 bits of information transformed by the MD4, MD5, SHA1, or RIPEMD-160 algorithms. The user supplies the 64 bits in the form of 6 English words that are generated by a secure computer. This implementation of s/key is RFC 1938 compliant.

When skey is invoked as otp-method, skey will use method as the hash function where method is currently one of md4, md5, sha1, or rmd160.

If you misspell your password while running skey, you will get a list of passwords that will not work, and no indication of the problem.

Password sequence numbers count backwards. You can enter the passwords using small letters, even though skey prints them capitalized.

The options are as follows:

-n count
    Prints out count one-time passwords. The default is to print one.

-p password
    Uses password as the secret password. Use of this option is discouraged as your secret password could be visible in a process listing.

-x  Causes output to be in hexadecimal instead of ASCII.

-md4
    Selects MD4 as the hash algorithm.

-md5
    Selects MD5 as the hash algorithm.

-sha1
    Selects SHA-1 (NIST Secure Hash Algorithm Revision 1) as the hash algorithm.

-rmd160
    Selects RMD-160 (160 bit Ripe Message Digest) as the hash algorithm.

EXAMPLES

% skey 99 th91334

Enter secret password: <your secret password is entered here>

OMEN US HORN OMIT BACK AHOY

%

SEE ALSO
login(1), skeyinfo(1), skeyinit(1)

RFC1938

TRADEMARKS AND PATENTS
S/Key is a Trademark of Bellcore.

AUTHORS
Phil Karn, Neil M. Haller, John S. Walden, Scott Chasin