End-to-end data integrity means making sure the data you send from one source to another is correctly and securely delivered. Think of it like mailing a letter: you want to make sure the contents of your letter are exactly the same by the time it reaches the person it's intended for. End-to-end data integrity is similar- it makes sure whatever data you send is the same as when it was sent, and didn't get changed, corrupted, or lost along the way. To make this happen, computers use encryption and authentication to protect data while it is in transit. That way, you can be sure the data you have is exactly the same data the other person has.