Internet blocking in Cuba – “Silencing dissidents in the name of moral and good manners”

June 8, 2020

Cuba has become infamous for blocking regime-critical content, and seldom provides any explanation other than the content failed to comply with the governments definition of “moral and good manners”. CubaNet and Tremenda Nota are two news sites that are blocked in Cuba.

CubaNet has traditionally being blocked in Cuba since its launch in 1994. However, the site has been unblocked two times, July 2015 – July 2016 (12 months) and July 2018 – February 2019 (6 months). The last blocking took place in February 2019, right before the referendum to approve the new constitution, and it remains blocked until today.

Tremenda Nota was launched in December 2017 and remained opened in Cuba until February 2019 when it was suddenly blocked. Apparently, the reason for the blocking was the publication of a piece on an opinion poll conducted by the government that showed that Cubans did not oppose same-sex marriages whose result was not made public. The results of the poll were not published because the government, apparently to please religious groups, wanted to eliminate the article in the Constitution that would have opened the door to same-sex marriage.

It might be surprising that the Cuban government blocks an LGBT-focused news site such as Tremenda Nota. The reason is that the government wants to own the LGBT process, and only allow once single voice for the LGBT movement, which is their own.

– Hugo Landa, Executive Director, CubaNet/Tremenda Nota

Despite repeated requests to the Ministry of Communication, to provide an official reason for the blockings, none has been given. CubaNet has reached out to the Ministry of Communications via email (, but is still waiting for an answer.

As a result of the blocking, and the failure of the Ministry of Communications to provide a valid reason for the blocking, Qurium has deployed Bifrost mirrors for the two sites. The two blocked sites are now available to the Cuban population via:

During the past year, several legal instruments have been approved in Cuba dealing with the implementation and regulation of information and communication technologies (ICTs) under the supervision of the Ministry of Communications (Mincom). In July 2019, the Government gazette of the Ministry of Justice published the coming into force of Decree-Law 370/218.

Although the law has received positive feedback in how it aims to improve computer security in the country, Article 68 contains vague descriptions of what the Government of Cuba understands as the obligation of hosting content inside the country (clause f) or what is as a violation to “to disseminate, through public networks of data transmission, information contrary to the social interest, morals, good manners and integrity of people” (clause i).

(f) hospedar un sitio en servidores ubicados en un país extranjero, que no sea como espejo o réplica del sitio principal en servidores ubicados en territorio nacional;

(i) difundir, a través de las redes públicas de transmisión de datos, información contraria al interés social, la moral, las buenas costumbres y la integridad de las personas.

Host locally

According to a clarification posted in Granma just a few days after the announcement, the obligation of “hosting locally” does NOT apply to individual bloggers but to websites that offer services to the citizens. It remains unclear if this requirement also applies to online media.

To our knowledge, there is only one service provider in Cuba for bloggers, namely Reflejos which is run by the Youth Computer Club. The platform reserves the rights to remove any content that does not follow the Conditions of Use or that in any form is “questionable”.

Moral and good manners

It is also unclear what is a violation of “moral and good manners” and how such cases are being handled. Despite the positive changes in the 2019 amended Cuban Constitution that prohibits all discrimination on the basis of gender, gender identity and sexual orientation; it remains unclear what falls under the category of “moral and good manners”.

Status of Internet blocking in Cuba

Following the study performed by OONI in 2019, Qurium carried out a number of in-county tests in late 2019 focusing on the blocking techniques in use by the Cuban government. The following eight blocked sites were tested and analyzed.

URLIP blockHTTP blockHTTPS blockComment
adncuba.comXUnblocked Redirect on http (to blocked https)
diariodecuba.comXXUnblocked without www
periodicocubano.comXUnblocked Redirect on http (to blocked https)
revistaelestornudo.comXUnblocked Redirect on http (to blocked https)
Unblocked without www

Fingerprinting the blocking

Two fingerprints are easy to identify in the blockings:

  • The presence of the HTTP header V2R2C00-IAE/1. is associated with Huawei’s eSight, a network management software for routers, switches and firewalls. The header IAE suggest the presence of a “Intelligent Awareness Engine”, that might refer to a Huawei NIP6000, an advanced New Generation Intrusion Prevention System (NGIPS) that support Session Disconnects.

 HTTP/1.1 503 Service Unavaliable
Status Code: 503
Server: V2R2C00-IAE/1.0
  • The presence of Deep Packet Inspection equipment that silently drops the sessions without Reset traffic (RST). Inspection of packages is taking place “inline”.


The technologies used to block websites in Cuba are technically incoherent. Some websites are blocked by IP address, while other sites have their HTTP (non-encrypted) traffic blocked but not their encrypted (HTTPS) traffic.

The presence of the V2R2C00-IAE header in some “Web Filtering” responses suggests the presence of a NIP product (Huawei Intrusion Detection System) that sits inline in the network.

The Web Filtering is performed without informing the readers the reason of the blocking and whether such blocking is compliant with the current legal regulations.