is a hybrid cryptosystem that combines some of the best available cryptographic algorithms and has become the open-source de facto standard for encryption and authentication of e-mail and file storage applications.

Pretty Good Privacy (PGP) is the correct answer of this question.

Explanation:

Pretty Good Privacy (PGP) is a hybrid cryptosystem that incorporates some of the best available routing protocols and has become the defacto free software framework for email and cloud storage applications to be encrypted and authenticated.

assuming you are in the home page.

1) go to the upper right hand corner

2) click on your "profile picture"

3) go down to "edit profile"

4) it should be titled as "edit your profile", click on "profile picture"

5) choose a file

6) press "change"

you're profile picture is updated

~