Microsoft ADV180005: Document signing deprecation in XPS Viewer

Description

Microsoft has deprecated the Document Signing functionality in XPS Viewer. This functionality relied upon the SHA-1 algorithm and is part of our overall effort to remove this algorithm from our products. This change impacts XPS Viewer on all supported versions of Windows. FAQ 1. I need to use this deprecated functionality. Is there a way to enable it? Yes. Please create the following registry entry: [HKEY_CURRENT_USER\Software\Microsoft\XPSViewer] "EnableDigitalSignatures"=dword:00000001 2. What risks am I accepting by using SHA-1 based document signing? SHA-1 is a legacy cryptographic hash that many in the security community believe is no longer secure. Using the SHA-1 hashing algorithm in document signing could allow an attacker to spoof content, perform phishing attacks, or otherwise manipulate content of a document. Microsoft, in collaboration with other members of the industry, is working to phase out the SHA-1 algorithm and to warn consumers of the possible risk when they encounter websites using the SHA-1 algorithm.