What's the most secure way to ensure one account per user in a cross-platform mobile app?

Question

I'm working on a polling system, and I want to prevent people from making multiple accounts or generating accounts with a bot. It will have clients on iOS, Android, and web. How can I best protect the integrity of the polling data?

Answer 1

电话验证（例如SMS或语音回叫）应具有合理的保护性。