Ian G wrote, On 2008-11-20 07:53: > Graham Leggett wrote: >> Having designed a system that includes "web signing" using >> crypto.signtext() for an insurance company to handle claim approvals, I >> can tell you that the primary question of the business people who used >> the system was "just what are we signing exactly?". > > OK, that's interesting but equally worrying that the business people > were asking that question, above all others.
Really? It seems to me that ANY prudent person would ask that question when asked to sign anything. I know, lots of people will sign anything they are asked to sign, and most of them do not suffer, because most people who ask for signatures are not trying to achieve evil ends. But I read every document that I am asked to sign in its entirety, and I would be stunned if a person who is asked to sign a "document" with a company issued credential would not ask the same. There are many places in the world where you don't want to have signed a document agreeing to certain things. You don't want to sign something critical of the government in China. You don't want to sign something sympathetic to radical Islam in the USA. You don't want to sign something taking sides in one of the ancient disputes in regions such as the former Yugoslavia or Czechoslovakia, in may parts of the world. People don't need to be lawyers to be aware of the risks of blindly signing things. >> In the case of crypto.signtext(), the end user is presented with a piece >> of human readable text, and the end user can choose to sign or not sign >> that human readable text, as appropriate. That user readable text is the >> beginning and end of what they are asked to sign. > OK, and how do you show afterwards that they signed it? I did a little > googling and found something called the "Netscape verification tool" ... > I would hope there is more to it than that, to put it mildly. IIRC, crypto.signtext produces a "document" that is in an IETF standard format, known as "Cryptographic Message Syntax" (CMS, originally known as PKCS#7), which is also the signature format used in S/MIME. There is lots of software in the world that can read such documents and verify the signatures. > Seriously, it is a business risk. It may also be a personal risk. > It isn't a security risk unless the business says it is a business risk, > *and* they accept the security solution. My employer has a LONG list of "acceptable business practices". Employees are forbidden to do a whole bunch of things, including making agreements with parties taking positions against other parties. It's surprising how many people will try to get you to sign a statement condemning certain nations (or religions or ethnicities) of the world, as a condition of doing business with them. My employer promotes the use of digital signatures, and it's particularly important not to sign something like the documents to which I've alluded above. I don't think these requirements of my employer are exceptional. > Anders is correct, you are wrong. I think such statements are supposed to begin with the word "Fiat". > If you approach this > problem as if "security" can solve it, you're in trouble from day one. > > Seriously. So, you're saying that making the content of the document being signed visible to the signer is to be "in trouble", and not a contribution to the signer's security? _______________________________________________ dev-tech-crypto mailing list [email protected] https://lists.mozilla.org/listinfo/dev-tech-crypto
