See how to view the details for signatures and certificates.

Find all release notes for the Xbox Update Preview Alpha ring here.

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 It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired.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

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

This article has guidance for: IT administrators who need visibility into Secure Boot certificate update status from their Intune enrolled Windows devices Organizations preparing for the June 2026 Secure Boot certificate expiration deadline Teams that want to monitor certificate rollout progress across their Intune enrolled Windows devices In this article: Introduction Prerequisites Detection ...

Applies to: Windows Server 2019 This security update includes fixes and quality improvements that are part of the following update: February 10, 2026—KB5075904 (OS Build 17763.8389) The following is a summary of the issues that this update addresses when you install this update. The bold text within the brackets indicates the item or area of the change we are documenting. [Windows System ...

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

This security update includes fixes and quality improvements that are part of the following updates: April 14, 2026—KB5082200 (OS Builds 19045.7184 and 19044.7184) The following is a summary of the issues that this update addresses when you install this update. If there are new features, it lists them as well. The bold text within the brackets indicates the item or area of the change we are ...

Find out how to get support for Microsoft apps and services.

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 ...