In this method, there are 2 parties and there are 2 keys that are generated:
- A public key that is sent to one party.
- A private key that remains with the other party.
- The message is encrypted using the public key and opened with the private key.
The security of this method relies on that the private key is secret and only the party receiving the message has access to it.
The public/private keys are created using different mathematical algorithms, the most famous is based on factorization of a large number into primes and it is known as RSA.
It is quick to multiply two very large numbers, but it takes a lot more time to factorize a large number into prime factors. To hack RSA and obtain the private key from the public key we would need to be able to factorize a very large number with more than 600 digits.
- No algorithm or machine is known today that is able to do such thing.
- It would take more than a million years of computation time to solve