GnuPG "classic" for Debian
==========================

gnupg1 is the "classic" version of GnuPG (branch 1.4), maintained for
people who really need the backward compatibility it provides.

Since mid-2016, Debian ships the "modern" version of GnuPG as gnupg.
Please use the gnupg package unless you know for sure that you need
gnupg1.

The main differences between "classic" and "modern":

 * "classic" has fewer dependencies than "modern"; improvements to
   underlying libraries must be explicitly ported to "classic"

 " "classic" accepts the known-broken PGPv3 key format, which "modern"
   rejects

 * "classic" has no support for S/MIME

 * "classic" has no support for elliptic curves

 * "classic" uses gpg-agent only as a passphrase cache, while "modern"
   offloads all secret key access to the agent

 * "classic" cannot auto-launch the agent

 * "classic" does not support the TOFU trust model

 * "classic" lacks some other tools useful for desktop environments

 * "modern" prefers the keybox format (~/.gnupg/pubring.kbx) for
   public keyrings; "classic" only knows how to use the traditional
   linear keyring (~/gnupg/pubring.gpg)

Note also that the "classic" and "modern" versions of gpg, while
capable of sharing a ~/.gnupg home directory, will not necessarily
access the same secret keys or public keys.  It is not advisable to
mix the two.

It is recommended to use gnupg instead of gnupg1.

 -- Daniel Kahn Gillmor <dkg@fifthhorseman.net>, Wed, 15 Feb 2017 10:35:11 -0500