Hi all, We would like to implement/integrate digital signature solution with third party document management solution(which has Rich API). We looked at commercial digital signature solutions and it looked like they are not affordable at all for Non-Profit org in India.I'm lead developer on this module. Reuirement- - Web signing: Sign documents(Doc,XLS,PDF,Tiff) online from ASP.NET DMS solution), they have viewer - Offline verifiablity : When documents are sent via email to someone outside organisation, how they can verify that document is from outside source. My Findings- - We can use Crypto API / CAPICOM to get certificate and sign it and put signature embedded in Doc,Xls,PDF file. - For offline verifiablity who does not have DMS solution, some thick app could be given who looks for signature in Doc,Xls,PDF file and tells signer, CA, Sign date. Problems- Embedded signature : Client need to have Office installed to sign document, even though he does not need to edit document. Detached signature : Document can not be verified outside Organisation or DMS solution. It looks like I'm missing something, please shad some light or just share your views on it.We are free to dig if theres any open source API to do this. Thanks, Maulik. We all are angles with only one wing, only way we can fly is to cooperate.