Twitter is planning to introduce the use of security keys as the only authentication method for accounts that have two-factor authentication enabled. At the moment, people who use security keys must have an extra authentication method such as SMS codes.
Authentication methods such as Google Authenticator have been found to be more secure than using SMS codes for two-factor authentication. However, security keys that connect to your computer through USB and Bluetooth have deemed the most effective means of securing your accounts online. Users do not have to type codes that can easily be intercepted by third-parties.
To use the security keys, connect the keys (using USB/Bluetooth) to the computer/laptop, the browser will issue a challenge which the key will cryptographically solve and sign you in to your account. A benefit of using security keys is that you need not give Twitter additional personal information such as your phone number.
Twitter said it will now allow multiple security keys for a single account. The platform has so far been allowing users to use a single security key along with two-factor authentication.
The company has not announced when the security key only authentication will take place.