Swiss-based Proton, the company behind popular online services like email and cloud storage, has developed its own CAPTCHA system to differentiate between genuine login attempts and bots. Dubbed "Proton CAPTCHA," this new service claims to be the world’s first censorship-resistant CAPTCHA solution.
The Need for a Custom Solution
According to Proton, existing CAPTCHA services were not meeting their requirements in terms of usability, accessibility, cultural biases, and security. In a blog post, Eamonn Maguire, former Facebook engineer and head of Proton’s machine learning team, explained the motivation behind creating their own solution:
"As we investigated available CAPTCHA options, we weren’t satisfied, so we decided to develop our own. Our primary goal was to provide a system that doesn’t compromise on privacy, usability, and accessibility, or security."
The Problems with Existing CAPTCHAs
CAPTCHAs (Completely Automated Public Turing Test to Tell Computers and Humans Apart) have been used for years to prevent bots from creating multiple accounts or accessing someone else’s account through credential stuffing. However, they often come with trade-offs in terms of usability, accessibility, cultural biases, and annoyances.
Companies like Apple and Cloudflare have sought alternative mechanisms to differentiate between humans and bots using device and telemetry data. But this raises concerns about data privacy, which is a core aspect of Proton’s business model.
Proton CAPTCHA: A Censorship-Resistant Solution
Proton CAPTCHA includes several notable features designed to bypass the limitations of existing CAPTCHA services:
- Multipronged approach: It displays both computational challenges and visual challenges, adapting to the user’s device and adjusting difficulty levels accordingly.
- Escalating difficulty: If it detects foul play, it increases the difficulty level of the proof-of-work challenge for bots but allows humans to pass quickly.
- Interactive puzzles: Proton CAPTCHA includes interactive puzzles with animations, making it more engaging and user-friendly.
Censorship-Resistant Features
Proton has also integrated censorship-resistant technologies into its CAPTCHA service. These features allow the system to work even in countries where internet restrictions are in place:
- Alternative routing: Proton uses alternative routing to find paths around restricted servers, enabling users in these regions to access its services.
- Unique needs: Proton’s own solution has resolved current CAPTCHA availability issues for users in restricted areas.
Conclusion
Proton’s development of a censorship-resistant CAPTCHA service marks an important step in addressing the limitations of existing solutions. By prioritizing usability, accessibility, and security, Proton has created a system that not only meets but exceeds the expectations of its users.
As the online landscape continues to evolve, innovative solutions like Proton CAPTCHA will play a crucial role in safeguarding user experiences and protecting against malicious activities.
About the Author
Eamonn Maguire is the head of machine learning at Proton. With over a decade of experience in developing AI-powered systems, he has worked on various projects that focus on improving user security and accessibility.
