Idag var der pludseligt en stor overraskelse til folk med den nye digitalsignatur, NemID. Det var ikke en kritisk fejl, men dog en enkelt fejl i en sandsynlig række af kommende fejl. Jeg kan ikke forstå hvorfor folk er overbeviste om at det er det sikreste system i verden, og der kan aldrig ske nogen form for misbrug.
I den ‘gamle’ digitale signatur lå filen på din egen computer, og ville en ægte skurk have fat i 100 digitale signaturer, skulle han bryde ind på 100 computere. Med NemID ligger alle filerne på en samlet server, og det kræver kun at man bryder ind på 1 computer for at få fat i dem alle….Gæt selv om det er et mere fristende mål end tidligere, hvor der nærmest ikke fandt misbrug sted. Og så kommer argumentet : Jamen man skal da bruge engangskoder til NemID, det kan jo ikke stjæles. Nej, men der er et program der har lavet disse koder, og et program der checker at den rigtige kode bliver anvendt. Kunne man forestille sig så moderne en forbryder at han ville kunne kopiere denne slags programmer, eller snyde dem med et tredje program?
De ældre af jer dødelige vil måske huske Chaos Crew, som i 1980’erne gjorde det alle påstod var umuligt : De skaffede sig blueprints til Challenger runfærgen, og fik adgang til affyringskoderne til USA’s a-våben. Der skete ingenting, men det viste at selv de sikreste systemer kan brydes. Derfor kommer nu Alvin’s andet Bud : Du må ikke bruge Digitale Signaturer af nogen art, hvis disse regnes for juridisk bindende.
.
.
.
Today, people who use the new danish system with digital signature, EZID, got a little surprise. An error had been found in the system, and though it is not a critical error, it is probably just one in a long line of security breaches in this system. I can’t figure out how people can convince themselves that EZID is the safest system in the world, and no form of abuse will ever occur. In the old digital signature, you had a file on your own computer, and if a real world Bad Guy wanted 100 digital signatures for abuse, he would have to hack into 100 computers with this file on. With EZID, all the files are gathered on a central server, and now you just need to hack one single server to get access to all the danish digital signatures. Quite a bit more tempting than the old option, I assume. And then the second argument comes into play : Whoever has those signatures still need one-use-codes to use them (non danes : Along with the signature, you get a keycard with codes, when they are used you get a new card), and these can’t be stolen from a central place. Agreed, it can’t be stolen as easily. But there has to be a program which checks that the correct code is being used. Is it a possibility to copy that program (think alongside key-generators), or cheat them with a third program?
Perhaps those of you mortal who are of a certain age will remember the name Chaos Crew. It was a group who achieved quite a lot of fame in the late 1980’s, where they did what everyone said couldn’t be done : They got blueprints of the Challenger space shuttle, and gained access to the launch codes for the american nuclear missiles. Nothing happened, they called the police themselves, ut it showed that there is no such thing as a secure server. That brings me to the second Commandment : You are not allowed to use any kind of digital signatures, if these are considered legally binding.