Learn how to identify and open encrypted and protected emails no matter what email client you're using.

See how to view the details for signatures and certificates.

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 It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired.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 ...

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

Select Start , enter device manager. Then, select Device Manager from the search results.

Using Authenticator as a way to sign in If you have turned on passwordless, two-step, or multi-factor authentication for your account, use the following steps to sign-in: Go to the site where you want to sign in. Enter your username at the sign-in prompt and select Next. Select Send notification.

The Microsoft Authenticator app helps you sign into your accounts when you're using two-step verification.

Microsoft 365 lets you easily see and open files that others have shared with you via the cloud or email.

Use the Information Protection viewer to view protected files in Windows, Android, iOS, or Edge.

什么是安全启动？ 安全启动是统一可扩展固件接口中的一项安全功能， (基于 UEFI) 的固件，可帮助确保只有受信任的软件在设备的启动 (启动) 序列中运行。 它的工作原理是针对存储在设备固件中的一组受信任的数字证书 (（也称为证书颁发机构或 CA) ）验证预启动软件的数字签名。 作为行业标准 ...