Ten years after Edward Snowden’s revelations, traffic encryption has come a long way. If then the concept of “partitioning” prevails, i.e. hiding my network activities from the service providers of my choice, this could help against surveillance capitalism. As is often the case, politicians are on the wrong side, warning of “dark” scenarios and thus playing into the hands of surveillance capitalists.
Announcement
In the first decade after Edward Snowden, developers, Internet companies and activists have (almost) put an end to the observation of data traffic on the Internet complete with bogus encryption. From the basic security of the HTTP web protocol with TLS to the completely new TCP successor Quic, in which encryption is already integrated, to the different variants of encrypted DNS (DNS over TLS, DoT; DNS over HTTPS, DoH) – unencrypted data streams are now a rarity.
Dare, look who
Blocking curious observers during packet transmission is only the first step. It’s not enough, as former Internet Engineering Task Force (IETF) chair Jari Arkko describes his fellow developers in a recent document again cordially.
Rather, it can be important to prevent the endpoints involved in the communication process from seeing what a user says and does. The server, even one from a service provider, that the user uses could be compromised or malicious, Arkko explains. Or their interest is simply not congruent with that of the user.
Arkko, who assumed the chairmanship of the IETF in the summer of the NSA-sponsored Russ Housely’s Snowden revelations and recently resigned from the Internet Architecture Board, points out, “We also face new attackers and risks. of various Internet services to consider.” Especially when a partner specified in the communication protocol is very interested in the data collection itself, it is important to provide additional security measures, even towards this end of the line.
The “Principle of Least Privilege (PoLP)” must be respected. This means that every program and every user of a system should operate on the very basis of the rights it absolutely needs to do its job. Also from the point of view of technical effectiveness, it is good that no party has all the information.
Announcement
Decoupling/Partitioning
Arkko’s colleagues at the IAB no longer need to be convinced of this concept.
The current president of the IAB, Mirja Kühlewind, also an Ericsson researcher, together with two members of the IAB, dedicated their draft to the idea of ”divide and conquer” data. In Partitioning as an architecture for private communication Kühlewind, Apple developer Tommy Pauly, and Cloudflare developer Christopher Wood present many of the protocols for which the IETF working groups are currently using the principle. Apple, Cloudflare and also Google developers are significantly involved in the work on various partitioning protocols. Even the term “decoupling” it is used for the distribution of information (and therefore power).
In principle, the simplest variant of information distribution already offers TLS, write Kühlewind and colleagues. In the future, transport encryption will only allow the client, TLS intermediaries, and destination server to see the actual content. Only the metadata and IP headers are visible to the outside world. Of course, without further data distribution, this offers no protection against the inspection and aggregation of metadata and identifying content by the intermediaries themselves.
“Encrypting a data exchange over HTTP prevents the central box, which sees a client’s IP address, from knowing the identity of the user account. But the TLS termination server sees both and can correlate them,” say the authors.
Specifications unaware
The most recent trend towards partitioning was started by groups who were looking to make DNS more private. As an excuse that with DNS over HTTPS (DoH) there’s suddenly more centralization of DNS traffic on large platforms – Firefox’s DoH traffic ends up on Cloudflare, for example – the creators of DoH had their idea of splitting DNS requests across several proxies.
While a first proxy receives the encrypted request from a requesting client, the destination server receives the question about the content, but does not know who it originally came from. A basic requirement for Oblivious DNS over HTTPS (ODOH) is that the different proxies do not cooperate. Otherwise, the metadata identifying the requester can be reconciled with the pages on which he or she traveled.
The developers at Apple and Cloudflare liked the basic framework for ODoH so much that they immediately applied it to HTTP traffic.
TO HTTP the client sends its requests through an “unaware” relay that cannot read the contents of the request to an “unaware” gateway that can decrypt the message but cannot identify the requesting client and cannot address it directly. Hybrid public key cryptography is used for encryption, which combines symmetric and asymmetric cryptography.
Mask, PPM, Privacy Pass
However, the various specifications of Oblivious are by no means all draft partitioning protocols.
According to Kühlewind, Pauly and Wood, this also includes work on Masque (Multiplexed Application Substrate over QUIC Encryption) and PrivacyPass. Older proxies for tunneling IP and UDP traffic over HTTP already ensured such privacy-friendly traffic splitting.
As Google engineer David Schinazi writes in one of the latest papers, increasing confidentiality requires the activation of several proxies.
With QUIC-based HTTP/3, a user can reach their destination server with end-to-end encryption and hide their path via several Connect UDP tunnels, Schinazi promises.
What’s missing: In the fast-paced world of technology, there’s often time to sort through all the news and background information. On the weekend we want to take it, follow the back paths away from the current, try different perspectives and make the nuances audible.
At the same time, QUIC and HTTP3 demonstrate the remarkable triumph of the web protocol as the universal substrate of the Internet. “The IETF has worked hard to deliver the Web over port 80 and HTTPS only, and to drop unencrypted traffic over port 80 (TCP/UDP/SCTP),” says Geoff Huston, chief scientist at APNIC, when asked asked by heise online.
The IETF PrivacyPass working group aims to help separate users’ IDs from information about their respective access to certain services. The authentication required for the services is carried out using “tokens” which are previously purchased anonymously from the issuing offices. The concept used for this is well known, it is the blind signatures designed by David Chaum.
