schoolDataManager

Answer to my own question:doh: Plan cryptography and encryption settings for Office 2013 "If you have to encrypt Office documents, we recommend that you save the documents as Open XML Format files (.docx, .xlsx, .pptx, and so on) instead of Office 97–2003 format (.doc, .xls, .ppt, and so on). The encryption that is used for binary documents (.doc, .xls, .ppt) uses RC4. It isn’t recommended, as discussed in Security Considerations sections 4.3.2 and 4.3.3 of the Office Document Cryptography Structure Specification. Documents that are saved in the older Office binary formats can only be encrypted by using RC4 to maintain compatibility with older versions of Office. AES, the default and recommended encryption algorithm, is used to encrypt Open XML Format files." Though this does still leave me wondering how I am to save documents securely with macros, but I suppose the answer is simply that I am not.

Hi, I have a spreadsheet in .xlsb format which is protected with 'password to open' to which I want to add a Excel 4.0 macro worksheet. I know that I can save it as .xls and add the macro sheet, however, I am unsure if this will compromise the level of encryption provided. Searching the internet I can't find a definitive answer as to whether the level of encryption is linked to the version of Excel used to save the file, or the document format used. Please could someone advise me as to whether saving as a .xls will lead to the file becoming no longer secure. Thanks, Vin