Signing your email messages with a digital ID helps to prove your identity and prevent message tampering.

Xbox Support 提供有关 Xbox、Game Pass 和账单问题的帮助，并通过社区提供建议和客户服务。

Note: Starting February 2026, we will introduce Jailbreak/Root detection for work/school Entra credentials in Microsoft Authenticator. This change enhances security by preventing Authenticator Entra credentials from functioning on jailbroken or rooted devices. Learn more.

Certificate authority (CA) A certificate authority is an entity similar to a notary public. It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired. Top of Page Digital signature assurances The following terms and definitions show what assurances are provided by digital signatures. Authenticity The signer is ...

Review our answers to your frequently asked questions about the Xbox Accessibility Insider League.

About digital signatures and certificates in Office, and buying a digital certificate from a certificate authority or create your own.

Sign-in options Usage Guidelines URL: Privacy Policy URL: ...

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Three ways to add copyright or trademark symbols to your Outlook messages.

Alpha Skip-Ahead Ring (2502.250120-2200) Hey Xbox Insiders! We are releasing a new Xbox Update Preview to the Alpha Skip-Ahead ring today. Continue reading below to learn all about what's included with this update.