protocol blocking

Protocol blocking is a security measure that restricts or disables outdated authentication methods to reduce vulnerability to attacks. On WindowsForum.com, discussions focus on Microsoft's enforcement of protocol blocking in Microsoft 365, particularly the phase-out of legacy authentication protocols like Basic Authentication starting July 2025. This move, part of Microsoft's Secure Future Initiative and Secure by Default strategy, requires administrators to consent to third-party app access and blocks non-compliant protocols. Users share experiences with enabling protocol blocking via Conditional Access policies, Exchange Online settings, and Azure AD, highlighting its role in preventing credential theft and unauthorized access. The tag covers practical implications for IT administrators managing tenant security, migration challenges, and compliance with modern authentication standards.