Quick set up guide for Encrypted Client Hello (ECH)

The Encrypted Client Hello (ECH) mechanism draft-spec is a way to plug a few privacy-holes that remain in the Transport Layer Security (TLS) protocol that’s used as the security layer for the web. OpenSSL is a widely used library that provides an implementation of the TLS protocol. The DEfO project has developed an implementation of ECH for OpenSSL, and proof-of-concept implementations of various clients and servers that use OpenSSL, and other TLS libraries, as a demonstration and for interoperability testing. [Read More]

DEfO - Developing ECH for OpenSSL (round two)

Encrypted ClientHello (ECH) plugs a privacy-hole in TLS, hiding previously visible details from network observers. The most important being the name of the web-site the client wishes to visit (the Server Name Indication or SNI). This can be a major privacy leak, like when accessing a dissident news source hosted on a Content Delivery Network (CDN). A visible domain name also provides a straightforward method for censors to block websites and internet services. [Read More]

Implementing TLS Encrypted Client Hello

As part of the DEfO project, we have been working on accelerating the development Encrypted Client Hello (ECH) as standardized by the IETF. ECH is the next step in improving Transport Layer Security (TLS). TLS is one of the basic building blocks of the internet, it is what puts the S in HTTPS. The ECH standard is nearing completion. That is exciting because ECH can encrypt the last plaintext TLS metadata that it is possible to encrypt. [Read More]

Tracking usage without tracking people

One thing that has become very clear over the past years is that there is a lot of value in data about people. Of course, the most well known examples these days are advertising and spy agencies, but tracking data is useful for many more things. For example, when trying to build software that is intuitive and easy to use, having real data about how people are using the software can make a massive difference when developers and designers are working on improving their software. [Read More]

Tweaking HTTPS for Better Security

The HTTPS protocol is based on TLS and SSL, which are standard ways to negotiate encrypted connections. There is a lot of complexity in the protocols and lots of config options, but luckily most of the config options can be ignored since the defaults are fine. But there are some things worth tweaking to ensure that as many connections as possible are using reliable encryption ciphers while providing forward secrecy. A connection with forward secrecy provides protection to past transactions even if the server’s HTTPS private key/certificate is stolen or compromised. [Read More]