One Time Password (S/Key) for Mobile Phone (J2ME)


S/Key Generator for J2ME architecture. An RFC2289 compliant One-Time Password generator for mobile phone supporting Java language. It uses MD4 and MD5 hash algorithms. This project starts from the project jotp: The Java OTP Calculator by Harry Mantakos and from its sources. Some features are:

News Highlights


You can download all the available versions here.


The following documentation is available:

Verify release

It is essential that you verify the integrity of the downloaded files using the PGP signature or the SHA1 or MD5 checksums. The checksums are not as strong indicators as the PGP signature.

The PGP signatures can be verified using PGP or GPG. First download the KEYS as well as the asc signature file for the particular distribution. Verify the signatures using

% pgpk -a KEYS
% pgpv <FILE_NAME>.asc
% pgp -ka KEYS
% pgp <FILE_NAME>.asc
% gpg --import KEYS
% gpg --verify <FILE_NAME>.asc

Alternatively, you can verify the checksums using *sum tools:

% md5sum -c <FILE_NAME>.md5
% sha1sum -c <FILE_NAME>.sha

Unix programs called md5/sha1 or md5sum/sha1sum are included in many unix distributions. *sum is also available as part of GNU Textutils. Windows users can get binary md5 programs from here or here. fsum and MD5Summer support MD5 and SHA1.

I highly recommend to verify the PGP signature, though.


This program is very simple... Logo