Are digital signatures good for complex documents – say MS-Word?
Digital signatures offer enormous benefits if they can be got down to securing bits of text (or cells in spreadsheets) rather than just whole documents. However, so far the main manufacturers have not really left first base on this one. There are some smaller suppliers who have thought this one through and are offering interesting products. Major problems occur when WYSIWYG – what you see isn’t what you got! XML is a fine case for this where embedded links may not be complete at the time of signing. In law, a contract is both the form and format of the contract document. So if a change to a table format would produce a completely different legal result, any system would have to be prevented from being able to do that. On the plus side, if both parties retain copies of signed documents this is likely to be much better than the paper based system.
