With the sender's Cards in place, we are now ready to ensure the Data IntegrityGuarantees a receiver that their data has not been altered over its life-cycle more ... by creating a Digital SignatureA Digital Signature can be used with any kind of message, so the receiver can be sure of the sender's identity and that the message arrived intact more .... This signature ensures that no third party modified any of the message's content and that they can trust a sender.
// prepare a message
NSString *message = @"Hey Bob, hope you are doing well.";
// generate signature
NSData *signature = [aliceKey generateSignatureForString:message error:nil];
To create a signature, you will need to load Alice's Virgil KeyThe Virgil Key is a wrapper of the user's secure Private Key more .... The Loading Key guide provides more details.
The Sender is now ready to transmit the signature and message to the Receiver.