RSA Encryption in 250 words or less

The RSA Algorithm, created in the 1970’s, is the predominant asymmetric encryption system used globally.

As noted previously, asymmetric public and private keys are related and can be used to encrypt and decrypt messages. This means that the core part of the RSA algorithm is key generation. Kid RSA is a simplified version of the RSA algorithm used for teaching purposes and below is an a Kid RSA example I created.

From above, the key values used for message encryption and decryption are the following:

• N = 437
• Public Key = 13
• Private Key = 61

Here’s how they are used.

Notice that the original message of “75” is input into the encryption engine, resulting in a cipher text of 151. The receiver inputs the cipher text of 151 into the decryption engine, resulting in a message of “75”, which is the same as the original message and we’ve gone full circle. That is, we’ve encrypted a message into a cipher text and then decrypted that cipher text back into the original message. Note that this is a pedagogical example and the full RSA algorithm is much more complex.

So, why use asymmetric encryption when its so much more complex than symmetric encryption?