TikTok is not be the first app to be scrutinized over the potential exposure of U.S. user data, but it is the first widely used app that the U.S. government has proposed banning over privacy and security concerns.
So far, the discussion has focused on whether TikTok should be banned. There has been little discussion of whether TikTok could be banned, and there has been almost no discussion of the effects on cybersecurity that a TikTok ban could cause, including encouraging users to sidestep built-in security mechanisms to bypass a ban and access the app.
As a cybersecurity researcher, I see potential risks if the U.S. attempts to ban TikTok. The type of risk depends on the type of ban.
Blocking TikTok in the network
Blocking access to TikTok by filtering traffic destined for addresses believed to be owned by TikTok is possible but would be difficult to accomplish. Server addresses can be changed and a TikTok ban could devolve into a game of cat and mouse.
Additionally, this sort of block could be bypassed using virtual private networks (VPNs), which encrypt data flowing between servers and devices. VPNs can be used to shield traffic between servers in other countries and devices in the U.S. VPNs were once widely recommended for people using public Wi-Fi, and people are already using VPNs to access blocked streaming services. While security experts no longer recommend VPNs for public Wi-Fi, many people have used them and so are familiar with a tool that would help them bypass a TikTok ban.
DNS sinkholes are another technique that could be used in TikTok bans. DNS, the Domain Name System, is a network protocol that behaves like the internet’s phone book. Computers need to know the IP address of a server in order to communicate with it. DNS allows a computer to look up that address using a name convenient for humans to remember, such as www.google.com.
How the Domain Name System works.
DNS sinkholes stop that lookup. DNS sinkholes don’t directly block access to a server. Rather, they stop other computers from being able to look up the server’s address. It’s fair to think of a DNS sinkhole as removing someone’s name from a phone book.
DNS sinkholes are often used to stop malware and advertisements. They could be used in a TikTok ban. However, DNS sinkholes only work if lookups are confined to DNS servers that are configured to be sinkholes. A ban using DNS sinkholes would likely cover most DNS servers that people’s computers use by default.
However, you can relatively easily change DNS settings on your computer to circumvent a ban based on DNS sinkholes. There are many public DNS servers that people could use instead of their current DNS servers, which are commonly maintained by internet service providers. Blocking TikTok with DNS sinkholes would require significant international cooperation to make it difficult for people to find DNS servers that…