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# How RSA Encryption Works

Games : Codes And Ciphers

RSA is a type of encryption known as public key encryption. That is anyone can access the specific public key and therefore encrypt. But the key is that the key is asymmetric: it will encrypt data but it will not decrypt data. Only someone with the private key can perform the decryption.

The underlying way in which RSA encryption works is to exploit what is effectively a one way function. That is, if you find the product of two large prime numbers, then the only way to get back to 'p' and 'q', the two base primes, is through a slow and arduous process of factoring.

Now, to find 'p' and 'q' for the number '21' is pretty easy: we know through our maths that p and q are here 3 and 7. However, when the end number is the product of two 1024 bit prime numbers (very large numbers) then it is slightly time consuming to find the correct numbers.

In fact it is not time consuming - it is estimated it would take all the computers connected together more than the lifetime of the universe to find the primes that create just one key!

This is because factoring is such a slow process, and it is because of this combination of the slowness of factoring and an asymmetric encryption process that makes RSA so powerful and revolutionary compared to previous systems of encryption.

By: Fred