Why did the security conscious engineer refuse to pay their dinner bill?

Because they could not verify the checksum.

More dad jokes you'll groan at

When does a sandwich cook? When it’s bakin’ lettuce and tomato! 🥓🥬🍅Why did the meatballs tell the spaghetti to go to sleep? It was pasta bedtime 🍝💤What did the skillet eat on its birthday? Pan-cakes.Why did the tomato turn red? Because it saw the salad dressing.What did one plate say to the other? Dinner is on me!If Bert Newton was a butcher...how would he introduce his wife? Meat Patty!