Requirements on using a certificate for signing

[MHA_EUC]

Hi , I have given an ecdsa cert and its corresponding root ca paths full trust in adobe reader dc . However under usage options , i am still unable to select the cert for signing. 

What requirements of a cert is required for it to be able to be selected for signing ? or is ecdsa certs not supported ? 
The key usage for the cert has digital signature enabled and the cert is in a smart card. 

Thank you. 

[eden_6762]

I wouldn't recomment self-signing for documents. For Adobe docs, there are speacial certs avaible in the market. Like this one from Comodo - https://cheapsslweb.com/email-identity/document-signing-certificate

They also offer SSL certs just in case.