Lets try a thought experiment. Imagine for a moment someone came to this forum in 1990 proposing say lossy packet routing could never possibly work because nobody could rely on such a system, pointing out that the Internet was minute compared to the telephone system and that therefore the Internet could never possibly be built. Furthermore the fact that the OSI networking stack was poorly specified and X.500 would inevitably fail meant that the Internet could not possibly work. Imagine what the response would be. Perhaps a pointer to an existence proof? Perhaps RTFM? Yes, there are serious problems with the PKIX model, there are also serious problems with the PGP model. There are even bigger problems with the 'X.500 will come and solve the problems of PKI model'. That is why all the major PKI vendors have abandonded those models (OK some cling to X.500 but only to suck up to customers, they don't believe in that stuff any more than I do). PKI is doing just fine thank you. If you need one to solve a specific problem it can be done. If you start from the position that any solution must be entirely costless you will have problems, but if you are realistic there are solutions that save cost overall. >> You are telling if someone else was given a certificate in my name and >> signed a virus code and distributed it. I would go to jail for it >> because it was signed in my name. >Check with a lawyer - and note that the spammers are *already* using things >like Jeem trojans to relay their spam. If they've got that much of a >foothold on your machine, adding code to sign the spam with your private key >is pretty trivial, really.... IANAL... and neither it appears are you... According to the ABA digital signature guidelines a digital signature should create a REBUTTABLE presumption of validity. That is exactly the same as the standard for a written signature, it is assumed to be valid unless you affirmatively claim it to be invalid. You might well have other issues if your machine is cracked and used to attack someone else. There might be claims of negligence etc. but I am not aware of such claims being made in cases to date... The grandmother loses her private key and loses her house thing was analyzed to death when the laws were being written. You probably don't want to ever use S/MIME as a mechanism to create promiscuous contracts. You might however want to use the fact that all your emails are S/MIME signed to defend yourself against claims that someone appropriated your signature. Phill