Cato Events: The Mind of the Censor and the Eye of the Beholder

On October 28, 2021, the Cato Institute hosted a symposium dedicated to Robert Corn-Revere’s forthcoming book, The Mind of the Censor and the Eye of the Beholder: The First Amendment and the Censor’s Dilemma.

The Foundation for Individual Rights in Education also had an interview with Corn-Revere this week.

Ralph Nader’s Censorious View of the State

Ralph Nader thinks the state should punish NPR and other radio stations for interrupting or failing to broadcast Donald Trump’s November 5 election speech. In his speech, Trump repeatedly lied about the election results.

This sort of censorship is the inevitable outcome of the regulatory overreach that Nader has advocated for all his life.

China Blocking TLS 1.3 Using ESNI

China is apparently blocking all HTTPS traffic that uses TLS 1.3’s ESNI. The folks at the Geneva project have a detailed report about what triggers the censorship.

With previous version of TLS, although the traffic between a computer and a server would be encrypted, the Server Name Indication (SNI) field allowed ISPs to determine which website the user was communicating with.

TLS 1.3 fixes that by introducing Encrypted SNI (ESNI), so that it is impossible for ISPs or other entities to see what website the user is trying to access. As the report notes,

ESNI has the potential to complicate nation-states’ abilities to censor HTTPS content; rather than be able to block only connections to specific websites, ESNI would require censors to block all TLS connections to specific servers. We do confirm that this is now happening in China!

. . .

Comparing the traffic captured on both endpoints, we find the GFW [Great Firewall] blocks ESNI connections by dropping packets from clients to servers.

This has two differences from how the GFW censors other commonly-used protocols. First, the GFW censors (non-encrypted) SNI and HTTP by injecting forged TCP RSTs to both server and client; conversely, we have observed no injected packets from the GFW to censor ESNI traffic. Second, the GFW drops traffic from server to client to block Tor and Shadowsocks servers; however, it drops only client-to-server packets when censoring ESNI.

We further note the GFW does not distinguish the flags of TCP packets when dropping them. (This is different from some censorship systems in Iran which do not drop packets with RST or FIN flags.)

The Geneva project report goes on to describe a number of strategies to evade this censorship.

John Stuart Mill On Censorship

The peculiar evil of silencing the expression of opinion is, that it is robbing the human race; posterity as well as the existing generation; those who dissent from the opinion, still more than those who hold it. If the opinion is right, they are deprived of the opportunity of exchanging error for truth: if wrong, they lose, what is almost as great a benefit, the clearer perception and livelier impression of truth, produced by its collision with error.

–John Stuart Mill, On Liberty, 1859