# Required certificate key usage for signing document

What's the required key usage/extended key usage for signing documents, eg.PDF, Word, PowerPoint, Excel, etc...

I am going to create a self-signed certificate that is needed to sign those documents. I wonder which key usage is required as there are many types that I can choose.

Note: I just need a self-signed certificate, not from trusted CAs.

You can use key usage as digitalSignature only to create a self-signed signing certificate for signing documents.

You can also use Microsoft proprietary Document Signing EKU: https://www.alvestrand.no/objectid/1.3.6.1.4.1.311.3.10.3.12.html.