The Iranian government is reportedly blocking access to websites that use the HTTPS security protocol, and preventing the use of software residents use to bypass the state-run firewall.

From post on Hacker News today, apparently written by an Iranian resident:

Since Thursday Iranian government has shutted [sic] down the https protocol which has caused almost all google services (gmail, and google.com itself) to become inaccessible. Almost all websites that reply on Google APIs (like wolfram alpha) won't work. Accessing to any website that replies on https (just imaging how many websites use this protocol, from Arch Wiki to bank websites). Also accessing many proxies is also impossible.

Several Hacker News users confirmed the original post's statement that Iran is blocking encrypted Internet traffic. "I live in Iran. The fact about the shut down is correct," one person wrote. Another said "They drop all encrypted connections. This means no https, no IMAP over TLS and no SSH connections. (Im in Iran)."

People are debating whether the shutdown is related to the 33rd anniversary of the Islamic Revolution, which is being celebrated by the government but has spurred protests in years past. This may not be the case, as one person writes "SSH has been disabled for a few months."

According to the Washington Post, Internet users are increasingly seeing the error message "According to computer crime regulations, access to this Web site is denied." The Post's bureau chief in Tehran, Thomas Erdbrink, says that software Iranians use to bypass Iran's firewall recently stopped working. "Many fear that the disabling of the software used to bypass the state-run firewall heralds the coming of what authorities have labeled the National Internet," Erdbrink wrote.

It's not clear how widespread the blockages are. Reports from some Twitter users earlier this week indicate that all non-Iranian websites had been censored. However, checking out the "Blocked In Iran" tool today shows no blockages of Google sites. Assuming the reports are true, it wouldn't be the first time websites have been blocked in Iran—Ars itself was blocked in October 2010 following coverage of the Stuxnet malware that targeted Iran.