Multiple digital signatures?

Hello OSUmike03,

Here is an article that may apply to your situation, especially if you are using Excel 2007. Click the link below...

The digital signature is lost when you use an earlier version of an Office program to open a file that was saved in a 2007 Office program

Sincerely,
Leith Ross

It sounds like you need something like RSA encryption.

Each authorizer combines their name and the current time, encrypts it with their own private key (a big prime number), and adds the cyphertext to the document.

The fact that anyone can apply the authorizers' public keys (another big prime number) to decrypt the signatures verifies their authenticity.

Originally Posted by shg

It sounds like you need something like RSA encryption.

Each authorizer combines their name and the current time, encrypts it with their own private key (a big prime number), and adds the cyphertext to the document.

The fact that anyone can apply the authorizers' public keys (another big prime number) to decrypt the signatures verifies their authenticity.

Could you link me to more information about this, or just describe it better? I don't deal with encryption much, so this is all foreign to me.

http://www.youdzone.com/signature.html
http://en.wikipedia.org/wiki/Digital_signature
http://en.wikipedia.org/wiki/RSA
http://rsa.com/


Google digital signatures for many, many hits.

I have a similar issue. We use a service request form to authorize purchases, work orders and changes. Right now its an Excel form and has to be printed, signed, scanned and emailed by the manager to the request department.

There is also a 2nd signature required for certain situations. As you can see the process is cumbersome to say the least.

Ultimately, I would like to be able to open the form from our intranet page, complete the form and forward it by email to the manager. The problem is, when the form arrives by email and the manager tries to sign it, there is a message that says the document cannot be signed because it was opened in "read only" mode yet I can edit other portions of the document with no problem.

I have removed the Protected Mode on excel and Outlook (this would not be viable in an organization our size anyway.) but I still get the error.

Anyone know why it says read only mode and how to get around this?

Originally Posted by Leith Ross

Hello OSUmike03,

Here is an article that may apply to your situation, especially if you are using Excel 2007. Click the link below...

The digital signature is lost when you use an earlier version of an Office program to open a file that was saved in a 2007 Office program

Sincerely,
Leith Ross

We actually run on Microsoft Office 2003, so we don't have problems with moving things from Excel 07 to Excel 03...since all we use is Excel 03.