Excel digital signatures

Hi KevinO'Dwyer2,

I go through your post carefully and as per your description, could you please confirm what digital signature you are using and whether you are using default Excel signature? so we can understand the issue and provide our suggestion in a productive manner, perhaps some related screenshots will be helpful.

Based on my test on default Excel signature have no issue and can't be verified certificate but can proceed.

Also, please upload your Excel account screenshot for our refence (open Excel> File > Account > Production Information and share a screenshot of it.  (Please mask your private information.)

As you mentioned “Once the certificate is renewed there is no problem with any new signatures but all previous signatures remain as expired and therefore invalid. How can I rectify it so that previous signatures do not become invalid when the certificate expires” sound like you are using the third-party certification if yes, then you may contact Microsoft Root Certificate Program Members certification provider for expert help.

I appreciate your patience and understanding.

Best Regards

Waqas Muhammad

Waqas,

Thanks for your reply.

Not sure what you mean default Excel signature but I have screenshot as much info as possible.

This is the signature box I sign.

This is my signature when the certificate is in date.

This signature was signed in October when the certificate was in date. When the certificate expired in November the error message came up on all signatures signed pre- November.

Any other info required please let me know,

Much appreciated

Kevin O’Dwyer

PII is mask by MSFT

Hi KevinO'Dwyer2,

Thanks for sharing updates with us. As per you mentioned screenshot it seems is not like default Excel signature e.g., Microsoft Office signature lines or Stamp signature lines as like in my below screenshot and this can't be verified certificate. 

It seems you Add signature services. However, based on my research about this, please try to check the workaround to try the steps in this mentioned KB: This document contains invalid signatures

I appreciate your patience and understanding.

Best Regards

Waqas Muhammad

Hi KevinO'Dwyer2,

Thanks for sharing updates with us. As per you mentioned screenshot it seems is not like default Excel signature e.g., Microsoft Office signature lines or Stamp signature lines as like in my below screenshot and this can't be verified certificate. 

 

 

                                                   

It seems you Add signature services. However, based on my research about this, please try to check the workaround to try the steps in this mentioned KB: This document contains invalid signatures

 

I appreciate your patience and understanding.

Best Regards

Waqas Muhammad

Waqas,

Thanks for your reply,

I understand about changing the calculation to manual, however I don't think this is a signature issue as they don't become invalid. The problem seems to be with the certificate in that they become "expired".

When a signature is input it is ok but as soon as the certificate expires the signature becomes "expired".

Although this was signed when the certificate was in date it obviously ignores the date it was signed and checks the date of expiry.

This means that all signatures are only valid for a maximum of one year .

I understand the need for renewing certificates annually but surely the system allows for historic signatures to remain without an error message (expired certificate) if the certificate was in date at the time of signing.

I hope I've explained this succinctly,

Thanks

Kevin O'Dwyer

 Hi KevinO'Dwyer2,

Thanks for sharing updates with us.  

First please accept my apologize for late reply du to out of work.

I understand when the certificate expires the digital signature becomes "expired" as well and cannot be use previous digital signature (still show expired) even after newel certificate and you want to allow for historic signatures to remain the previous digital signature without an expired error message after newel certificate.

Please allow me a time and I check this behavior with related team, and I will post back when I get updates information ASAP.

Appreciate your patience and understanding. 

Best Regards, 

Waqas Muhammad 

Thank You very much Waqas.

I look forward to your reply,

Thanks

Kevin

 Hi KevinO'Dwyer2,

Regarding to your concern "previous digital signatures remain when certificate becomes expires"  I have consulted with our senior  and they  recommend that if you don't mind could you please contact certificate provider to know the expected behavior.

Meanwhile, I research a lot regarding to when the certificate becomes expires but unfortunately I cannot find information mentioned in official article. But I found the only valid signature which are time stamped by a secure time-stamp server will be valid even after expiration.

I appreciate your patience and understanding.

Best Regards

Waqas Muhammad

Waqas,

It's been a while since I last corresponded with you as I have been liaising with my IT department. After some investigation they tell me that they have contacted Microsoft who has said that the certificates are set up that way.

I gathered from you this has nothing to do with Microsoft but the certificate provider. Is it possible you could definitely confirm this is fact before I talk to my IT department again.

Thanks

Kevin