Charles wants to encrypt his email communications. How can he do that? Leo says that your email can go through dozens of servers before getting to the person you addressed it to. And everyone along the way can read it unless it's encrypted. It's more like a postcard, but without federal privacy protection. PGP (Pretty Good Protection) uses public-key cryptography, which has two different keys. One public, and one private. Only you can encrypt with the private key, while the public key is used to verify and open the email. You can give the public key to anyone.
Brian's doctor is sending him emails that are encrypted. He's supposed to click on a link and then log into GoDaddy to see it, but it doesn't really work. Leo says the doctor is sending the additional security to maintain HIPPA compliance and he's using a third party encryption to do it. Since it's not really accessible to Brian because he's blind, Leo says he should advise them that it isn't working. Leo advises GPG, public key crypto. It uses one key to encrypt, and another to decrypt. Once it's set up, it's outstanding and safe.
Chris doesn't know what to do since his Apple GPG tools don't work with macOS Sierra. Leo says that GPG is Gnu Privacy Guard, which is the open source version of Pretty Good Privacy email encryption. You can use any email client with it to encrypt your email. The other side has to be able to decrypt it, though.
The internet is a public place, and whatever you post to it is out of your control. The one exception to this is encrypting your data, however. This will ensure that only you and the recipient will be able to read the data. Here are a few open source tools for public key encryption:
Using the Paris attack to justify stepping up the intrusiveness of state surveillance, UK Prime Minister David Cameron is calling for and end to any communication that the government is unable to read with a simple warrant signed by the home secretary. Leo says that this can't happen. The US even tried to prevent strong encryption by classifying it as munitions, and it just didn't work because it's really easy to create strong encryption.