The security features of portal.office.com are designed to protect users' data and enhance organizational security. Key features include multi-factor authentication (MFA), which requires users to verify their identity through multiple methods. Data encryption safeguards data in transit and at rest, while Advanced Threat Protection (ATP) defends against malware and phishing attacks. Conditional access policies control access based on user location, device, and risk level. Additionally, audit logs and compliance tools help monitor and ensure regulatory adherence. Identity Protection leverages machine learning to detect and respond to suspicious activities, ensuring a secure and seamless experience for Office 365 users.