Although J2ME is a powerful technology for mobile application development, its current capabilities, particularly in the J2ME MID Profile, leave much to be desired when it comes to the level of security necessary for mobile commerce. The advent of SSL security for J2ME is an excellent first step for the growth of the platform. For more information on security offerings for J2ME, visit any of the links listed below.
Phaos Micro Foundation:
Bouncy Castle Crypto APIs: http://www.bouncycastle.org/