In this chapter, we worked with digital signatures and learned how to use them in RESTful web services. These days, digital signatures are often used because they guarantee message integrity, and information cannot be compromised while it is traveling from the sender to the receptor. We already know that information can be modified in transit, but when you're verifying the signed information, the receiver can notice it and take the actions that he/she believes are appropriate. For example, they can send another request to avoid working with corrupt information. At the end of this chapter, we worked with message body encryption, and we saw the difference between using these encryptions and HTTPS. Finally, we saw how the receiver, using the key, figured out the message body to make use of the information according to their needs.