Authy provides an elevated authentication solution that allows developers to protect their users with multiple channels such as SMS, voice, and email one-time passcodes, TOTP, Push notifications, and device-specific authentication. The Authy user model is based on a one-to-one correlation between a user's phone number and their Authy ID, which is used for API calls during two-factor authentication. The multi-device feature allows users to authenticate from any device they have added to their circle of trust, providing an additional layer of security when carrier access is unavailable. SMS is suitable for low-risk users, while device-specific TOTP and Push Authentication are recommended for high-net-worth individuals who require enhanced security. By implementing a multi-channel approach with escalated device identification, Authy provides a secure solution for sensitive use-cases.