J. Alex Halderman and his colleagues have unveiled Telex, a "state-level response to state-level censorship." It's a network of censorship-busting major ISPs that provide infrastructure-level, hard-to-detect proxying that allows people in repressive regimes to get access to sites blocked by their national firewalls. The descriptive materials on the site are very easy to grasp and very exciting.

* Telex operates in the network infrastructure — at any ISP between the censor's network and non-blocked portions of the Internet — rather than at network end points. This approach, which we call "end-to-middle" proxying, can make the system robust against countermeasures (such as blocking) by the censor.

* Telex focuses on avoiding detection by the censor. That is, it allows a user to circumvent a censor without alerting the censor to the act of circumvention. It complements anonymizing services like Tor (which focus on hiding with whom the user is attempting to communicate instead of that that the user is attempting to have an anonymous conversation) rather than replacing them.

* Telex employs a form of deep-packet inspection — a technology sometimes used to censor communication — and repurposes it to circumvent censorship.

* Other systems require distributing secrets, such as encryption keys or IP addresses, to individual users. If the censor discovers these secrets, it can block the system. With Telex, there are no secrets that need to be communicated to users in advance, only the publicly available client software.

* Telex can provide a state-level response to state-level censorship. We envision that friendly countries would create incentives for ISPs to deploy Telex.