>>> "Jens" == Jens Lechtenboerger <jens.lechtenboer...@fsfe.org> writes:
> On 2015-11-18, at 15:04, Uwe Brauer wrote: >> Correct but this applies to smime and gpg. > I’ll refer to this point below. >> [...] > No, please re-read the paragraph starting with: “If I cannot replace” So you are talking only about evil clear signed messages, which are sent by some smtpmail hacking, say in my name. Well this does not pass the reality check in my experience. People usually do not check clear signed messages, that is they do not check whether an un encrypted message is signed or not. They tend to check whether *encrypted* mails are signed. Now in order that the attacker sends an evil *encrypted and signed* message say in my name, to Joe Foo, this attacker needs the public key of Joe Foo. However in the smime model he usually cannot download that key from some server but has to interchange with Joe Foo smime signed messages (which include the public keys) so either at the end he needs to hack my mail account or obtain that key by some other more complicated (social) attacks. In order to do something similar in gpg the attacker needs to hack directly my account where I have my private gpg keys installed. Well. >> I don't see much of a difference between >> >> - the pgp scenario: to place a falsified pgp key on a server >> >> - the smime scenario: to crack a smime certificate by breaching a >> CA (which is more difficult that placing a falsified pgp key). > I agree to your above statement “Correct but this applies to smime > and gpg.” Thus, I consider the following attacks to be comparable: > Upload some OpenPGP key and register some S/MIME certificate. Agreed. > However, newbies are warned not to trust downloaded OpenPGP keys, > while I’m not aware of similar warnings for “trusted” (signed) > S/MIME certificates. Well most users I know are not over--enthusiastic about applying for a free certificate from a organisation they barely know[1], but in practise I tell them I will send them a signed message in 5 minutes which contains my public key. So they do not over trust that model and accept every key from everybody without thinking. But again my scenario is about having a on the fly encryption which works without much hassle for the newbies. A question I really would like to ask Edward Snowden is what he thinks about smime and whether NSA and friends have backdoors installed. >> Again the question was is smime easier to use. > No. The question was whether someone on this list uses S/MIME with > OpenSSL and would object to a change of defaults to epg. Right, the original question was that, but I made a point about the simplicity of the smime model. > The current topic is “Trust and public keys.” I changed that in > response to your e-mail where you stated: “Keys signed by these > authorities have to be trusted 100 \%.” Again by the model, not as an recommendation or a moral advice. > The ensuing discussion helped me to see clearer: There are S/MIME > certificates that have been issued without checks (except ability to > receive e-mail), which I find ridiculous given the goal of > certification. The situation is even worse than I thought > initially. Well you could go for a class 2 certificate.[2] But I admit I also learnt something about gpg: it is not as safe as I thought, since it seems to difficult to identify trusted public keys from a server. Best Uwe Footnotes: [1] and they are even worried that this organisation keeps a copy of their private key. That however I have checked, and seems not to happen with Comodo, I don't know the other organisations. [2] actually I don't know anybody who posses such a certificate. _______________________________________________ info-gnus-english mailing list info-gnus-english@gnu.org https://lists.gnu.org/mailman/listinfo/info-gnus-english