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

Xbox Support ... Xbox Support

See how to view the details for signatures and certificates.

The Xbox Offline System Update (OSU) process allows you to update your console by downloading a file to a USB flash drive and then installing that file directly onto your Xbox Series X|S or Xbox One console.

Introduction Windows updates released on and after February 13, 2024 include the ability to apply the Windows UEFI CA 2023 certificate to UEFI Secure Boot Allowed Signature Database (DB). Updating the DB will enable devices to receive future boot loader updates that are included in monthly updates. This is important because the existing certificate will expire and moving to the new certificate ...

This security update includes fixes and quality improvements that are part of the following updates: January 13, 2026—KB5073724 (OS Builds 19045.6807 and 19044.6807) January 17, 2026—KB5077796 (OS Builds 19045.6811 and 19044.6811) Out-of-band January 24, 2026—KB5078129 (OS Builds 19045.6812 and 19044.6812) Out-of-band The following is a summary of the issues that this update addresses ...

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 It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired.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

This article describes how you can digitally sign a macro project on Windows by using a certificate. If you don't already have a digital certificate, you'll need to get one.

摘要 Email 簽名能在你的商業溝通中建立專業一致性，並確保收件人在每則訊息中都擁有你的聯絡資訊。 在Outlook中，你可以為不同用途設定多個簽名 (內部與外部、個人與商務) ，並選擇是否自動包含在新郵件、回覆或轉寄中。 你的簽名可以包含文字、連結、圖片和圖片 (，例如你的手寫簽名或標誌 ...

Notes: If you don't see the security key option, it's possible that your organization doesn't allow you to use this option for verification. In this case, you'll need to choose another method or contact your organization's help desk for more assistance. Before you can register a security key, you must have at least one additional security verification method registered.