Ideem Passkeys+ is an authentication solution designed for payment and checkout flows. The product uses a Zero-Trust Secure Module (ZSM) that cryptographically binds to user devices to enable one-click checkout experiences. The solution operates by invisibly authenticating devices without requiring one-time passwords (OTPs) or application redirects. The ZSM creates cryptographic device bindings that allow the system to recognize trusted users automatically during checkout processes. Passkeys+ supports layered authentication, where the base ZSM device binding can be supplemented with passkey-based two-factor authentication for stronger security requirements. This approach is designed to meet Strong Customer Authentication (SCA) compliance standards. The product targets payment teams and merchants implementing digital wallets, Buy Now Pay Later (BNPL), and Pay by Bank checkout methods. The authentication mechanism works across multiple platforms and regions to provide consistent user experiences. The system aims to reduce checkout friction by eliminating manual verification steps while maintaining cryptographic security at the device level. The authentication process runs in the background during transactions without requiring explicit user interaction for trusted devices.