*Created originally on Bitbucket by [jtbraun (Jeremy Braun)](https://bitbucket.org/%7B3b51f7c4-294d-4492-8b26-2cc4cc9c7ad1%7D/)* openpyxl expects the workbookHashValue and workbookSaltValues to be HexBinary strings. However, excel can produce base64 encoded strings This documentation from Microsoft: https://msdn.microsoft.com/en-us/library/documentformat.openxml.spreadsheet.workbookprotection(v=office.15).aspx Calls out for both of these fields: The possible values for this attribute are defined by the W3C XML Schema base64Binary datatype. Here's another implementation (Java) that is consistent with the MSFT docs above. http://www.javafind.net/gate.jsp?q=/library/162/docx4j-3.1.0-javadoc/org/xlsx4j/sml/CTWorkbookProtection.html Note that revisionsHashValue and revisionsSaltValue are also supposed to be base64 data Currently, worksheets protected in this way fail to parse. *Attachments:* [workbook.xml](/uploads/f15087325d37bccf0d59bfbdc1346566/workbook.xml)