X-Git-Url: http://git.chise.org/gitweb/?a=blobdiff_plain;f=README;h=81a94abea80d0851b38e0fabbb30586e43f8ca74;hb=3c0243c9e94a1185749b53a334b3358fa0d5bd8f;hp=ca53e4af93a09e23e8963d8841ef5f0daac3a362;hpb=2686e015c9a74089405b8a5198d8db9b381e70e2;p=elisp%2Fepg.git

diff --git a/README b/README
index ca53e4a..81a94ab 100644
--- a/README
+++ b/README
@@ -1,64 +1,53 @@
 * 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
+
+NOTE: EasyPG is not a fork or a re-implementation of Gnus/PGG.
 
-** GNU Emacs 21.4 or later
+* Requirements
 
-** XEmacs 21.4 or later
+** GNU Emacs 21.4 or later, XEmacs 21.4 or later
 
 ** GnuPG 1.4.3 or later
 
-** Gnus 5.10.8 or later (optional)
-
 * Quick start
 
-** Transparent file encryption utility
+** Installation
 
-EasyPG provides transparent file encryption utility similar to
-crypt++, alpaca.el, hedgehog.  To try this feature, 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 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, 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 a temporary file.
+EasyPG does *not* use `call-process-region' to communicate with a gpg
+subprocess.
 
-*** `call-process-region' writes data in region to temporary files.
-
-`call-process-region' writes data in region to temporary files.  PGG
-and gpg.el use `call-process-region' to communicate with a gpg
-subprocess.  Your passphrases leak to the filesystem!
-
-*** 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
 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.  It is recommended that as
-soon as you are done with passphrase you should clear it manually.
-However, PGG and gpg.el can keep passphrase strings in cache for a
-while and this behavior is their default!
-
-** GnuPG features are directly accessible from Emacs
-
-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.
+strings may be moved elsewhere in memory.
+
+Fortunately, there is gpg-agent to cache passphrases in more secure
+way, so the EasyPG library dares *not* to cache passphrase by itself.
+Elisp programs can set `epg-context-passphrase-callback' to cache
+user's passphrases.