//// (. .) ___________________________o00-(_)-00o___________________________________ Hi, I am currently preparing a paper on payment systems for the Internet and related issues. I recently found out that so-called observers could be placed on smart cards (in order to prevent double spending, or even to prevent people from cheating on taxes...). To be honest that's about all I know about observers and I am very eager to find out more. I am, however, having a hard time finding interesting references on this subject. Hence, all suggestions to get me started would be extremely welcome. Questions of particular interest are: possible functions (and limits), how 'real' are they already?, what about privacy?, ... Many thanks in advance. leo _________________________________________________________________________ Leo Van Hove Centre for Financial Economics Vrije Universiteit Brussel (Free University of Brussels) Pleinlaan 2 B-1050 Brussels Vox: +32 629.21.25 Fax: +32 2 629.22.82 e-mail: lvhove@vnet3.vub.ac.be _________________________________________________________________________