Russian Government Restricts Access to Signal
Reports indicate that the Russian government is taking steps to restrict access to the encrypted messaging application Signal. This action, spearheaded by the regulatory body Roskomnadzor, is justified by claims that the app poses a risk as a communication tool for terrorists and extremists. According to the Russian news agency Interfax, Roskomnadzor stated, “User access to the messenger Signal is restricted…to prevent the use of the messenger for terrorist and extremist purposes.”
Technical Challenges for Users
Numerous users across Russia have reported experiencing difficulties when attempting to access Signal. For instance, new users attempting to register are met with error messages. The internet censorship watchdog NetBlocks has corroborated these reports, noting that its metrics indicate a significant restriction on Signal’s backends across most internet service providers in Russia.
In addition to Signal, the Russian government has also been throttling access to YouTube, citing concerns that the platform promotes anti-Russian sentiments. This broader pattern of internet censorship raises questions about the implications for communication and information sharing within the country.
Ukrainian analyst Viktor Kovalenko has suggested that the blocking of Signal may be a strategic move by Russia to hinder local users from disseminating information regarding the Ukrainian military's activities in the Kursk region. While Signal has not provided an official comment on the situation, the app acknowledged on social media that it is aware of reports regarding access restrictions in various countries, including Venezuela.
Circumventing Censorship
In light of these developments, Signal has recommended that affected users enable the app's built-in “censorship circumvention” feature. This option, found within the privacy settings under “advanced,” employs a technique known as “domain fronting.” This method allows internet traffic to be disguised as originating from a different source, potentially routing through larger mainstream platforms.
Signal can utilize services such as Google, Amazon CloudFront, Amazon S3, Azure, Cloudflare, Fastly, and Akamai to facilitate access once the circumvention features are activated. The rationale behind this approach is that in order to block Signal, censors would need to restrict access to these larger services, which would effectively mean disabling significant portions of the internet.
In a recent blog post, Signal elaborated on its ongoing efforts to develop additional anti-censorship techniques. However, challenges remain, particularly due to some platforms continuing to use plaintext Server Name Indication headers. This practice allows internet service providers to monitor which sites users are attempting to access. Signal highlighted that solutions like Encrypted Client Hello (ECH) could enhance privacy by removing the plaintext server name from the TLS handshake, making it more difficult for hostile ISPs to block access. Nonetheless, widespread support for such solutions is still lacking.
Historically, Russia has attempted similar measures against other messaging platforms, such as Telegram, but those efforts were ultimately abandoned. A combination of consumer VPN usage and Telegram's strategic hosting on third-party cloud providers reportedly enabled users to bypass those restrictions.