Hi, The Interlock Protocal (Applied Crypto 2nd. ed., pp. 49) is just exactly what I have been looking for to address the MITM issues in regards the data haven model I have been working on. I had completely forgotten about this technique. I should read AC more often...;) Thanks again for the pointer! ____________________________________________________________________ | | | The most powerful passion in life is not love or hate, | | but the desire to edit somebody elses words. | | | | Sign in Ed Barsis' office | | | | _____ The Armadillo Group | | ,::////;::-. Austin, Tx. USA | | /:'///// ``::>/|/ http://www.ssz.com/ | | .', |||| `/( e\ | | -====~~mm-'`-```-mm --'- Jim Choate | | ravage@ssz.com | | 512-451-7087 | |____________________________________________________________________|