Passkeys are a new form of authentication that replace traditional passwords, providing a phishing-resistant and streamlined sign-in process. Microsoft Password Manager allows users to save and synchronize passkeys across devices linked to their Microsoft accounts, enhancing accessibility. The architecture for passkey syncing includes confidential computing for sensitive operations, hardware-rooted key protection for encryption keys, tamper-evident recovery storage, and encrypted synchronization across devices. Sensitive passkey operations are executed in Azure's confidential computing environments, ensuring cryptographic materials are processed securely. The encryption keys are protected using Azure Managed HSM, with access governed by attestation-based mechanisms. Registration and recovery processes require user authentication and enforce security measures within confidential computing boundaries, including a lockout state after consecutive incorrect PIN attempts. The system aims to provide a secure and user-friendly experience as part of a transition to a passwordless future.