Today I publish a detailed rebuttal to the argument from the intelligence community that we need to break end-to-end encryption in order to protect children. This has led in the UK to the Online Safety Bill and in the EU to the proposed Child Sex Abuse Regulation, which has become known in Brussels as “chatcontrol”.
The intelligence community wants to break WhatsApp, as that carries everything from diplomatic and business negotiations to MPs’ wheeling and dealing. Both the UK and EU proposals will take powers to mandate scanning of both text and images in your phone before messages are encrypted and sent, or after they are received and decrypted.
This is justified with arguments around child protection, which require careful study. Most child abuse happens in dysfunctional families, with the abuser typically being the mother’s partner; technology is often abused as a means of extortion and control. Indecent images get shared with outsiders, and user reports of such images are a really important way of alerting the police to new cases. There are also abusers who look for vulnerable minors online, and here too it’s user reporting that does most of the work.
But it costs money to get moderators to respond to user reports of abuse, so the tech firms’ performance here is unimpressive. Facebook seems to be the best of a bad lot, while Twitter is awful – and so hosts a lot more abuse. There’s a strong case for laws to compel service providers to manage user reporting better, and the EU’s Digital Services Act goes some way in this direction. The Online Safety Bill should be amended to do the same, and we produced a policy paper on this last week.
But details matter, as it’s important to understand the many inappropriate laws, dysfunctional institutions and perverse incentives that get in the way of rational policies around the online aspects of crimes of sexual violence against minors. (The same holds for violent online political extremism, which is also used as an excuse for more censorship and surveillance.) We do indeed need to spend more money on reducing violent crime, but it should be spent locally on hiring more police officers and social workers to deal with family violence directly. We also need welfare reform to reduce the number of families living in poverty.
As for surveillance, it has not helped in the past and there is no real prospect that the measures now proposed would help in the future. I go through the relevant evidence in my paper and conclude that “chatcontrol” will not improve child protection, but damage it instead. It will also undermine human rights at a time when we need to face down authoritarians not just technologically and militarily, but morally as well. What’s the point of this struggle, if not to defend democracy, the rule of law, and human rights?
Edited to add: here is a video of a talk I gave on the paper at Digitalize.
There’s a good write-up of my paper in The Register
Your paper (indeed read via the register) is a brilliant rebuttal of a darned stupid approach to a problem that has been almost entirely misunderstood by those entrusted with solving it. I just hope they listen.
It’s also a perfectly valid denunciation of the general failure of “authorities” to do adequate homework before attempting to regulate complex problems, so it has much wider implications in principle than just child protection.
“chatcontrol” will not improve child protection, but damage it instead. It will also undermine human rights at a time when we need to face down authoritarians not just technologically and militarily, but morally as well.”
– I wouldn’t put it any better. You are 100% right.
Thanks for an interesting article.
Slightly off to the side, but I once wrote up how Slashdot and Nasdaq had each solved different parts of the moderation problem, similar to the report-criminality problem… https://leaflessca.wordpress.com/2020/06/21/composing-an-arbiter-of-truth/
The first thing to do is strip off the dog whistle / knee jerk “Think of the…”.
The real policy is to push the camel nose of corruption by those funded from the public purse, not just under the tent flap but everywhere as cheaply as possible.
Most people are their own worst enemies, I’ve repeatedly shown that no “Security App” can be secure because of the deficiencies of the way the “communications rnd point” works. The aithorities do not need to break the encryption or other security aspects of the application when they have easy access to the OS and thus device drivers and can simply access the user interface just as the user does. Worse is the fact files get transfered to “cloud backup” where they become “third party business records” at best.
The likes of GCHQ and the others who do what is illegal but nodded through, know this as do law enforcment. They want you to incorrectly think about what “End to End” realy is.
What they don’t want people realising is there is an easy solution that GCHQ nor Law Enforcment can stop. Which is,
“Move the security end point, beyond the communications end point.”
That way they can only get at ciphertext not plaintext…
To ensure this however requires putting in a choke point or air or preferably “energy gap” between the communications device and the security end point.
We’ve actually known this implicitly for thousands of years, and it’s the reason encryption exists seperately from communications. It remained true up untill the 1970’s and the start of Personal Computing, when it all went horribly wrong. Brcause of cost and now convenience encryption was brought onto the communications device and the millennia old security model was not just broken but shattered beyond belief. We should all know by now that the AES competition was a stich up by the NSA that new that,
1, Emphasising Speed
2, Making the Speed Code freely available.
Would result in code riddled with implementation based “Side Channels”. The NSA “list of crimes against security” is long and grevious as is that of GCHQ and other SigInt, IC and LE agencies.
Back in WWII SOE was betrayed by the British Secret Service that insisted on SOE using “Poem Codes” that were known to be extraordinarily weak, but worse very prone to Operator Error. Eventually after significant loss of life due to this dirty little bit of “turfwar fighting” SOE moved to the easier to use and usually fully secure One Time Pad.
Thus we should take a leaf out of that book. We should use a seperate to the communications device method of encryption used in what is in effect an “Off-Line” mode (which stops most of the side channel issues dead). Whilst I would not recommend the OTP due to KeyMat KeyMan issues it has the advantage of demonstrating what those agencies do not want being generally known. Which is they have no way to stop End to End Encryption, or of accessing the plain text, if the first and second communicating parties do not want them to. The only thing thr Agencies can do is “stop all communications” which is not as easy as most think.
Oh one advantage of the OTP you don’t hear get talked about is that it gives the first party Alice deniability if the second party Bob betrays them to a third party Eve. Because “All messages of the same length are equiprobable”so any ciphertext Eve has seen is also “All messages of the same length”. All Alice has to do is make KeyMat that gives an innocent message and avoid giving correlation by deed or action to the actual message Bob decoded and has handed over to Eve.