Policy

Encryption mode for Information Rights Management (IRM)

If you enable this policy setting, you can choose from two options for controlling the encryption mode that Excel, PowerPoint, Word, Visio, and Outlook applications use to protect content with Information Rights Management (IRM): - Electronic Codebook (ECB) – ECB mode is always used when applying IRM encryption. - Cipher Block Chaining (CBC) – CBC mode is always used when applying IRM encryption. If you disable or don't configure this policy setting: - For Microsoft 365 Apps (Version 2304 or later): Cipher Block Chaining (CBC) mode is used. - For earlier Microsoft 365 Apps and Office LTSC 2021, 2019, and 2016: Electronic Codebook (ECB) mode is used.

Policy
Pack Microsoft Office
Category Microsoft Office 2016 / Security Settings
Policy ID 23503e848d50
Internal name L_Encryptiontypeforirm

Registry

Copy registry mappings

HKCU\software\policies\microsoft\office\16.0\common\drm\compatibleencryption

Policy notes

If you enable this policy setting, you can choose from two options for controlling the encryption mode that Excel, PowerPoint, Word, Visio, and Outlook applications use to protect content with Information Rights Management (IRM): - Electronic Codebook (ECB) – ECB mode is always used when applying IRM encryption. - Cipher Block Chaining (CBC) – CBC mode is always used when applying IRM encryption. If you disable or don't configure this policy setting: - For Microsoft 365 Apps (Version 2304 or later): Cipher Block Chaining (CBC) mode is used. - For earlier Microsoft 365 Apps and Office LTSC 2021, 2019, and 2016: Electronic Codebook (ECB) mode is used.

Related policies

ActiveX Control InitializationAllow Basic Authentication prompts from network proxiesAllow file extensions for OLE embeddingAllow root or intermediate certificates as VBA trusted publishersAllow specified hosts to show Basic Authentication prompts to Office appsAllow VBA to load typelib references by path from untrusted intranet locationsAutomation Security