I am running through the securing TCP/IP of the N10-06 certification and having difficulty understanding the use of Hash. I get the process of using the algorithm to change the data, but what I don't understand is how that is applied and how it is decrypted on the receiving side to get the data. I have read that it is a One-Way system and cannot be decrypted, but if that is the case how does the recipient decrypt it? Is there a public key sent with the hash and what portion of my computer actually does the decryption. I've been Googling on this a while and reading Mike Myers book as well as Professor Messers video on it, but I am only getting vague descriptions on the intent and concept but not how its staged and executed. Does anyone have any sage advice on this?