KB5025823 Change in how .NET applications import X.509 certificates
If you need to import a passwordless private key certificate blob and you have determined that the blob is trustworthy, you can suppress the additional validation checks performed by the June 13, 2023, security release by calling a different constructor overload.
Exporting a digital certificate - Microsoft Support
If you have already configured Outlook for S/MIME, you can use the following steps to export a digital certificate. Open Outlook. Select File > Options > Trust Center > Trust Center Settings. Select Email Security. Under Digital IDs, select Import/Export. Select Export Your Digital ID to a file.
Applies To:
Outlook for Microsoft 365, Outlook 2021, Outlook 2019, Outlook 2016
Obtain a digital certificate and create a digital signature
Create a digital certificate to digitally sign a document immediately. If you do not want to purchase a digital certificate from a third-party certificate authority (CA), or if you want to digitally sign your document immediately, you can create your own digital certificate.
Applies To:
Excel for Microsoft 365, Word for Microsoft 365, Outlook for Microsoft 365, PowerPoint for Microsoft 365, Word 2021, Word 2019, Excel 2016, Word 2016, Outlook 2016, PowerPoint 2016, Office 2016, Excel 2013, Word 2013, Outlook 2013, PowerPoint 2013, Office 2013
Secure messages by using a digital signature - Microsoft Support
Click Import/Export to import a digital ID from a file on your computer, or click Get digital IDs to find a list of services that issue digital IDs for your use. Compose your message, and then send it.
Applies To:
Outlook for Microsoft 365, Outlook 2021, Outlook 2019, Outlook 2016, Outlook 2013
Digital signatures and certificates - Microsoft Support
A certificate is usually valid for a year, after which, the signer must renew, or get a new, signing certificate to establish identity. Note: You can learn more about public and private keys in this article.
Applies To:
Excel for Microsoft 365, Word for Microsoft 365, PowerPoint for Microsoft 365, Access for Microsoft 365, Visio Plan 2, Excel 2021, Word 2021, PowerPoint 2021, Access 2021, Visio Professional 2021, Visio Standard 2021, Excel 2019, Word 2019, PowerPoint 2019, Access 2019, Visio Professional 2019, Visio Standard 2019, Excel 2016, Word 2016, PowerPoint 2016, Access 2016, Visio Professional 2016, Visio Standard 2016
KB5028608 Change in how .NET Framework runtime imports X.509 Certificates
This failure affects PKCS#12 blobs which have been exported [e.g., via X509Certificate.Export(X509ContentType.Pfx)] without a password. The failure may occur non-deterministically. Workaround. Microsoft has released updated installers for .NET Framework and .NET to address this issue.
Encrypt messages by using S/MIME in Outlook on the web
Want to add a padlock to your email messages? You can use S/MIME in Outlook on the web to increase the security of messages. A digitally encrypted message can only be opened by recipients who have the correct key. A digital signature assures recipients that the message hasn’t been tampered with.
Applies To:
Outlook.com, Outlook on the web for Exchange Server 2016, Outlook on the web for Exchange Server 2019
Can I export my own certificate and email it to myself?
Can I export my own certificate and email it to myself? Yes. For more information, see Exporting a digital certificate.
Applies To:
Outlook for Android, Outlook for iOS
KB5014754: Certificate-based authentication changes on Windows domain ...
CVE-2022-34691, CVE-2022-26931 and CVE-2022-26923 address an elevation of privilege vulnerability that can occur when the Kerberos Key Distribution Center (KDC) is servicing a certificate-based authentication request.
A .pfx certificate file that does not have a private key is created ...
You run the Certificate Export Wizard to export a .pfx certificate file that was imported with the Enable strong private key protection setting enabled.