X-Git-Url: http://git.chise.org/gitweb/?a=blobdiff_plain;f=README;h=b438bd3330e83010f5e01ce59e33527d0b1ba665;hb=359180decf50389e8a5313a3fb04c88a6a93f69e;hp=bcf3731dcbb5faa2786e629e49e6a7fc669b2303;hpb=cd7a5af0110cb4e59e6d08fb8468c14610ff7cd1;p=elisp%2Fepg.git

diff --git a/README b/README
index bcf3731..b438bd3 100644
--- a/README
+++ b/README
@@ -1,71 +1,57 @@
 * What's this?
 
-EasyPG is yet another GnuPG interface for Emacs.  It consists of three
-parts: transparent file encryption utility, Gnus/PGG backend, and
-elisp library to interact with GnuPG.
+EasyPG is yet another GnuPG interface for Emacs.  It consists of two parts:
 
-* Requirements
+- "The EasyPG Assistant" which provides basic GUI of GnuPG
+- "The EasyPG Library" which enables use of various features of GnuPG
 
-** GNU Emacs 21.4 or later
+NOTE: EasyPG is neither a fork nor a re-implementation of Gnus/PGG.
 
-** XEmacs 21.4 or later
+* Requirements
 
-** GnuPG 1.4.3 or later
+** GNU Emacs 21.4 or XEmacs 21.4
 
-** Gnus 5.10.8 or later (optional)
+** GnuPG 1.4.3
 
 * Quick start
 
 ** Installation
 
-$ ./configure
-$ sudo make install
-
-** Transparent file encryption utility
-
-EasyPG provides transparent file encryption utility similar to
-crypt++, alpaca.el, hedgehog.  To try this, add the following line to
-your ~/.emacs and C-x C-f ~/test.txt.gpg.
+  $ ./configure
+  $ sudo make install
 
-(require 'epg-file)
+Add the following line to your ~/.emacs
 
-** Gnus/PGG backend
+  (require 'epa-setup)
 
-EasyPG provides an implementation of the backend interface of
-Gnus/PGG.  To use EasyPG instead of pgg-gpg, install pgg-epg.el and
-add the following line to your ~/.gnus.
+Then you can browse your keyring by M-x epa-list-keys.  In addition,
+you can do some cryptographic operations on dired.
 
-(setq pgg-scheme 'epg)
+  M-x dired
+  (mark some files)
+  : e (or M-x epg-dired-do-encrypt)
+  (select recipients and click [OK])
 
-* Advantages over other competitors
+* Security consideration
 
-There are many competitors of EasyPG such as Mailcrypt, Gnus/PGG,
-gpg.el, etc.  EasyPG has some advantages over them.
+** `call-process-region' writes data in region to a temporary file
 
-** EasyPG avoides potential security flaws of Emacs.
-
-*** `call-process-region' writes data in region to temporary files.
-
-`call-process-region' writes data in region to temporary files.
-EasyPG do _not_ use `call-process-region' to communicate with a gpg
+`call-process-region' writes data in region to a temporary file.
+EasyPG does *not* use `call-process-region' to communicate with a gpg
 subprocess.
 
-*** There is no way to clear strings safely.
+** `(fillarray string 0)' is not enough to clear passphrases
 
-If Emacs crashed and dumps core, passphrase strings in memory are also
+If Emacs crashes and dumps core, Lisp strings in memory are also
 dumped within the core file.  `read-passwd' function clears passphrase
 strings by `(fillarray string 0)'.  However, Emacs performs compaction
 in gc_sweep phase.  If GC happens before `fillarray', passphrase
-strings may be moved elsewhere in memory.
-
-Fortunately, there is gpg-agent to cache passphrases in more secure
-way, so EasyPG dares _not_ to cache passphrase.  Elisp programs can
-set `epg-context-passphrase-callback' to cache user's passphrases.
+strings may be moved elsewhere in memory.  Therefore, passphrase
+caching in Elisp is generally a bad idea.  The EasyPG Library dares to
+disable passphrase caching.
 
-** GnuPG features are directly accessible from Emacs
+Fortunately, there is more secure way to cache passphrases - use
+gpg-agent.
 
-Other competitors provide only specific features of GnuPG since they
-still support PGP 2.*, 5.*, 6.*.  As the name indicates, EasyPG is
-inspired by GPGME (GnuPG Made Easy), and the library interface is
-close to GPGME.  With EasyPG you can benefit from a lot of features of
-GnuPG.
+Elisp programs can set `epg-context-passphrase-callback' to cache
+user's passphrases, it is not recommended though.