Validating a digital signature
:) The pivotal part is that their is a pair of keys that were generated together. So giving you my public key, along with the encrypted data and signature as described is just about as trustworthy as giving you a business card that I had printed at Staples for $50.Next, to deal with a digital signature, the sender sends: The verifier performs the Decrypt operation above and compares his output with the original data. To really trust that I am who I say I am, and am therefore trust worthy, you need someone to sign off on my identity (like checking a driver's license).
Depending on how you have configured your application, validation may occur automatically.My understanding was that public keys encrypt, private keys decrypt... Your understanding of "public keys encrypt, private keys decrypt" is correct... To do that, you need to use something that only YOU have: your private key.A digital signature in its simplest description is a hash (SHA1, MD5, etc.) of the data (file, message, etc.) that is subsequently encrypted with the signer's private key.If the two are the same, he knows that the message was not tampered with, because only the sender has the private key, and there is no reasonable way to determine the private key from the public key. That's the Certificate Authority's job (CA for short).The CA has it's own key pair - and it uses it's private key to sign a digital certificate for the key holder.Signature validity is determined by checking the authenticity of the signature’s digital ID certificate status and document integrity: In Acrobat or Reader, the signature of a certified or signed document is valid if you and the signer have a trust relationship.
The trust level of the certificate indicates the actions for which you trust the signer.
In a PDF, most digital signatures are referred to as , because it’s used to identify the person signing it.
How can I verify the signatures and document's data integrity?
You can change the trust settings of certificates to allow specific actions.
For example, you can change the settings to enable the dynamic content and embedded Java Script within the certified document.
I am not able to understand that how the digital signature is verified.