A typo was discovered by Douglas Chrystall in the article.  In the section on Asymmetric Encryption, I wrote:

"You encrypt a message with your public key, and it can be decrypted by the receiver using your publicly available public key and their private key."

I meant to write:

"You encrypt a message with the receiver's public key, and it can be decrypted by the receiver using their private key."

Thanks for the catch Douglas!