* What's this?
-EasyPG is yet another GnuPG interface for Emacs. It consists of two
-parts: transparent file encryption utility and easy-to-use elisp
-library to interact with GnuPG.
+EasyPG is yet another GnuPG interface for Emacs. It consists of two parts:
-* Requirements
+epa.el - EasyPG Assistant, a basic GUI of GnuPG
+epg.el - the EasyPG library which interacts with 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
* Quick start
-(0) Put (require 'epg-file) in your ~/.emacs.el
+** Installation
-(1) Restart emacs
+$ ./configure
+$ sudo make install
-(2) C-x C-f ~/test.gpg
+Add the following line to your ~/.emacs
+
+(require 'epa-setup)
* Advantages over other competitors
-** EasyPG avoides potential security flaws of Emacs.
+There are many competitors of EasyPG such as Mailcrypt, Gnus/PGG,
+gpg.el, etc. EasyPG has some advantages over them.
+
+** EasyPG avoides potential security flaws of Emacs
+
+See "Security consideration" section.
+
+** 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.
+
+* Security consideration
-*** `call-process-region' writes data in region to a temporary file.
+** `call-process-region' writes data in region to a temporary file
-PGG and gpg.el use `call-process-region' to communicate with a gpg
-subprocess. Your passphrases may leak to the filesystem.
+`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
-dumped with the core file. `read-passwd' function clears passphrase
-strings by `(fillarray string 0)'. However, it is not perfect. Emacs
-does compaction of small strings in gc_sweep phase. If GC happens
-before `fillarray', passphrase strings may be copied elsewhere in
-memory. So, it is recommended that if you are done with passphrase
-you should clear it manually. However, PGG and gpg.el enables
-passphrase caching by default.
-
-** Most GnuPG features are accessible from Emacs
-
-As the name indicates, EasyPG is inspired by GPGME (GnuPG Made Easy),
-and the library interface is close to GPGME.
+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 the EasyPG library dares *not* to cache passphrase by itself.
+Elisp programs can set `epg-context-passphrase-callback' to cache
+user's passphrases.