Internet censoring: How the Cubans do it

The Cuban government has blocked Internet content deemed critical of the revolution from reaching users on the island for years, but apparently its censorship methods are not that sophisticated, according to a report by the Open Observatory of Network Interference (OONI), an organisation linked to the open network and free software, Tor.
After analysing access to more than 1,400 websites in three Cuban cities between late May and early June, three OONI members who travelled to the island found that at least 41 are blocked, mostly news sites and websites of Cuban opposition organisations or human rights NGOs.
“The main conclusion of this study is that Cuba’s ISP (Internet Service Provider, in this case ETECSA) appears to mainly censor sites that express criticism (directly or indirectly) toward the Cuban government,” explained Maria Xynou, one of the authors of the study. “However, Internet censorship in Cuba does not appear to be particularly sophisticated compared to other countries with more advanced censorship, such as China.”
The OONI team concluded that censorship is done using a method known as “deep packet inspection” (DPI), which allows filtering of data when passing through an inspection point.
Only versions of sites that use the HTPP – and not its secure version, the HTPPS – are blocked, potentially allowing users to bypass censorship by simply accessing secure versions of sites, the report indicates.
“Furthermore, while some sites that express political criticism were found to be blocked, many other international sites – which arguably express more criticism – were found to be accessible. This might indicate a lack in sophistication in both Internet surveillance and censorship implemented in the country,” said Xynou.
However, this could be a calculated strategy on the part of the Cuban government.
“It seems to us that countries make budget-influenced decisions when implementing censorship: generally, the objective is to discourage most people from accessing specific resources at a reasonable cost,” she added.
In the case of Cuba, the state telecommunications monopoly, ETECSA, controls Internet access, which is expensive and limited – although the company has pledged to expand connectivity.
An hour of Internet browsing costs $1.50 in a country where the average monthly salary is about $30. According to the most recent official statistics, about four million users have access to the Internet but most of them navigate through a government-controlled intranet. Cuban authorities do not define what they consider a “user” either. Across the country, there are only 370 public places with Wi-Fi service. Home service has not yet been implemented on the island.
“Given the high cost of accessing the Internet, rendering it inaccessible to most Cubans, perhaps the Cuban government doesn’t even need to invest in sophisticated Internet censorship (yet). Furthermore, the political climate of the country appears to foster self-censorship, which arguably is the most effective form of censorship,” Xynou said.
Since it launched in 2012, OONI has been mapping global censorship on the Internet in an effort to increase transparency. The organisation has developed free software to examine a network and gather information to determine who censors and how it’s done.
With this technology, the OONI team also verified that in Cuba censorship is carried out in a way that is not clear to the user. The user can’t tell if the site or service is blocked, or whether there is just a bad connection. This is the case with Skype, which is blocked on the island through a method known as “packet injection,” a technique that has been used in countries such as China and prevents users from realising if the service is intentionally blocked or not.
Although ETECSA uses the technology of the Chinese firm Huawei, the report authors could not determine if the same technology is used to censor.
“Our analysis of the Cuban Internet was limited to what we could observe publicly, at the network level, by sending and receiving data,” Xynou said. “It would have been much more difficult and also risky, to fully understand the internal implementation of the Cuban censorship apparatus. ... We decided not to go down that route.”