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ohmygodel | 7 years ago
I am reasonably familiar with the contents of GDPR, having looked into it more after attending a lecture on the subject [0].
> We cannot use IP address except for antifraud, so it is not legally viable for us to try to link zero-knowledge proofs into a profile based on IP address.
If your users must rely on you obeying a policy, then please just say that. Right now, it seems to me that you claim to use technical means to prevent Brave from learning browsing histories [1].
> my home AT&T IP address wanders often, so do many others; mobile even more variable.
IP addresses can be so identifying that they have been ruled as personally-identifiable information by the European Court of Justice [2].
> I think you are mistrusting prematurely. But as noted in my item 1, we are talking to PIA about using an IP relay (not full VPN). This got delayed by their work on handshake.org but we're restarting it.
Thank you for stating clearly that you aren't using PIA (aka "IP masking") at the moment for Brave Payments. You might consider your users who are worried about data breaches and compromised servers as much as they are worried about Brave's intentions. Please don't take my criticisms personally.
> Putting these through separate Tor circuits is possible, as we also randomly space them out in time.
Oh, you do randomly delay ballot submissions? I have not been able to find any such logic in the code but would be happy to be pointed to it. The specific way in which you choose delays is, of course, crucial to it providing security.
[0] <https://petsymposium.org/2018/program.php>
[1] <https://brave.com/faq-payments/#anonymous-contributions>
[2] <https://www.irishtimes.com/business/technology/european-cour....
BrendanEich|7 years ago
I did just say that, several times -- but with conditions that do not make it a matter of "policy" only. We agree IP address should be masked for self-funded users. Working on it!
We are very familiar with how any user log can be used as a history, but anonized proofs that can't link to a user id except illegally to IP address are not on the same level of threat as the Blendle, Flattrplus, etc. histories taken in the clear -- never mind Google et al. surveillance. To equate the tech and not make any distinctions does a disservice to us in my view. I'm not sure you did equate, but see next paragraph.
Tech alone is never enough for anything like what we are doing. Addresses matter, if not IP then on blockchain. There are side channels. There will be bugs. IMHO you have to include the social and legal constraints, too. Even a p2p with ZKP solution has some risk due to the blockchain addresses, which need purpose-limited terms under GDPR too.
On road, will get you links to code for randomizing time between ANONIZE sessions as soon as I can.
ohmygodel|7 years ago
You'd be surprised how far you can get. For example, protocol design exist that provide strong message anonymity: mixnets, DC-nets, and secure multiparty computation (MPC). Tor is great at its goals, but it accepts weaker security for low latency that Brave doesn't need. Tor is also unfortunately blocked in many companies and countries by technology and/or policy. Mixnets are freely available [0]. MPC is sold commercially [1]. (I have no personal or professional connection to either project.)
> On road, will get you links to code for randomizing time between ANONIZE sessions as soon as I can.
Looking forward to it.
Many thanks for the serious engagement. I look forward to recommending Brave to my friends and colleagues in the not-distant future!
[0] <https://katzenpost.mixnetworks.org> [1] <https://www.unboundtech.com/>
BrendanEich|7 years ago
JS implementation in Muon-based https://github.com/brave/browser-laptop product:
1. https://github.com/brave-intl/bat-client/blob/master/index.j...
2. https://github.com/brave-intl/bat-client/blob/master/index.j...
3. https://github.com/brave-intl/bat-client/blob/master/index.j...
From Marshall Rose: "the first deals with the delay in before asking for ballots (after a contribution) and the second deals with each delay between submitting each ballot."
New "brave-core" (chromium refork to get front end but w/o Google accounts/sync), the new implementation; narration by Serg Zhukovsky:
"""
here we make a first call https://github.com/brave-intl/bat-native-ledger/blob/reconci...
which calls that function https://github.com/brave-intl/bat-native-ledger/blob/reconci...
after the random wait it calls that function https://github.com/brave-intl/bat-native-ledger/blob/reconci...
and in it’s callback it goes all over again if there are still votes to send
if you are interested in the function that does the randomization, it’s here: https://github.com/brave-intl/bat-native-ledger/blob/reconci... """
The C++ is all new code, not yet released -- bug reports welcome! Thanks.