doublec from the command line

# first
keybase join  # if you're new, or
keybase login # if you're not.

# then
keybase push  # if you already have a public key, or
keybase gen   # if this is all new to you

keybase id doublec # verify identity proofs

keybase encrypt doublec -m 'a secret msg'
keybase encrypt doublec -s -m 'a signed secret msg'

# optionally track doublec, so you don't
# have to keep id'ing them, even when
# switching machines
keybase track doublec

# and psst, people you track are pulled into GPG too
gpg --encrypt # etc.

Once you're in, you can sign, verify, encrypt and decrypt in variety of ways. Check out the examples and, if necessary, the installation instructions. All the crypto is performed with GPG. For an overview of Keybase, check out our splash page.