# [Signature Module Options] dialog box

This dialog box appears when you select [Write Signature and Save As] from the [File] menu of Viewer. Select Signature modules to use.

- [Digital Certificate (SHA256 V8 or later)]
  You can sign a document using a Digital Certificate (SHA1 V5 or later) issued by a Certification Authority (CA). A person who received a signed DocuWorks document can take the signer's public key out of the certificate to verify the signature. By verifying the signature, you can confirm that the DocuWorks has not been altered since it was signed and that the signer is the authentic owner of the private key. This signature cannot be verified with DocuWorks Ver.7.x or earlier.
- [Digital Certificate]
  You can sign a document using a Digital Certificate issued by a Certification Authority (CA). A person who received a signed DocuWorks document can take the signer's public key out of the certificate to verify the signature. By verifying the signature, you can confirm that the DocuWorks has not been altered since it was signed and that the signer is the authentic owner of the private key. This signature cannot be verified with DocuWorks Ver.4.x or earlier.
- [DocuWorks Electronic Signature]
  You can use the Electronic Signatures stored in an Electronic Signature Case to sign documents. You can also verify the trustworthiness of the Electronic Signature by comparing the Signature in the Electronic Signature Case with the impression on the document. The public key cryptosystem with asynchronous algorithm is used. This signature cannot be verified with DocuWorks Ver.4.x or earlier.

Important
DocuWorks Electronic Signature does not use Digital Certificates issued by Certification Authority. When you print DocuWorks documents marked with the DocuWorks Electronic Signature imprint or the signature image of a Digital Certificate onto paper documents, the paper documents cannot be used as legal deeds or signed documents.

### [Always use this module from the next time onward.]

By checking this box, the document was signed in the selected way and [Signature Module Options] dialog box does not appear when you write Signature and save next time.
Note
To change the choices, use [Signature] under [DocuWorks Viewer Options] in the [Preferences] dialog box.