Want to learn how to send coded messages? You’ll never have to worry about someone “accidentally” reading what they’re not supposed to ever again. However, if someone is smart and decodes your message, you’ll have to use the second method I talk about in my presentation. Fermat’s Little Theorem helps in encoding and decoding these messages but good luck trying to hack into them because you will have to factor very large numbers into large prime numbers. It takes a century for a computer to factor a two hundred digit number into a product of primes.