|19:54 21.Mar 2019 MET|
I didn't collect much on Cryptography here yet, but you can download my public keys for Pretty good privacy (PGP) and GNU Privacy Guard (GPG). I had trouble using the pgp key with gpg (missing idea encryption which was enforced by the key) so you can grab either one depending on the program you intend to use.
To download the keys instead of displaying them in the webbrowser you probably have to shift-click or right-click and select from the menu. They are plain ASCII so you can also copy-paste them into an editor window without damaging them.
E-Mail is insecure. Whoever is sitting at a computer (or the local network of each of them) involved in transporting the mail to/from you can read and change it. Thats similar to a postcard everybody can read. Why don't you write everything as postcards? You don't want everybody to read them? Well why are you sending unencrypted E-mails? Modern strong encryption allows you to protect your E-mail from the wrong eyes or your friendly Bastard operators from hell from changing them into something you didn't intend to write. Asymmetric encrytion as implemented in pgp and GnuPG make the key exchange quite secure if one is a little bit careful.
Another option for sending mails to anybody without a prior key exchange is a cryptogaphic signature. The mail can be read by anybody, but you can prove if somebody was tampering with the content. Also if the recipient is interested and checks your signature he can be pretty sure (depending how much he trusts the public key he has from you) that the mail is indeed from you. This is another big problem on the Internet, as its extremely easy to fake ones identity. In Germany check with the c't cryptography campaign at www.heise.de to get your public key certified. Then the recipient of your mails can even be sure that you are who you say you are (at least the name is the one in your Passport).
There is an interesting page collecting a variety of crytography programs and security flaws. It has also a short statement on "ethics of spying" at the bottom of the page which is interesting to read.