X-Git-Url: http://git.chise.org/gitweb/?a=blobdiff_plain;f=README;h=d56f6df0e48b41477654e0f17f1f3d28a7b54ce2;hb=9959124798b862332baed742cf607e495144a583;hp=187db0d370eea27466b7151c501fe4d7a01fdecf;hpb=31d97193bafb50321267222e8e7db2489c4c43b0;p=elisp%2Fepg.git

diff --git a/README b/README
index 187db0d..d56f6df 100644
--- a/README
+++ b/README
@@ -1,8 +1,16 @@
 * What's this?
 
-EasyPG is yet another GnuPG interface for Emacs.  It consists of a
-transparent file encryption application and easy-to-use elisp library
-to interact with GnuPG.
+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.
+
+* Requirements
+
+** GNU Emacs 21.4 or later
+
+** XEmacs 21.4 or later
+
+** GnuPG 1.4.3 or later
 
 * Quick start
 
@@ -14,17 +22,32 @@ to interact with GnuPG.
 
 * Advantages over other competitors
 
+There are many competitors of EasyPG such as Mailcrypt, PGG, gpg.el,
+etc.  EasyPG has some advantages over them.
+
 ** EasyPG avoides potential security flaws of Emacs.
 
-*** `call-process-region' writes data in region to a temporary file.
-PGG and gpg.el use `call-process-region' to communicate with a
-subprocess "gpg".  So, your passphrases may leak to the filesystem.
+*** `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.
-To prevent passphrases from been stealing from cores, `read-passwd'
-function clears passphrase strings by `(fillarray string 0)'.
-However, it is not enough.  In GC sweep phase, Emacs does compaction
-on small strings.  If GC happens before `fillarray', passphrase
-strings may be copied elsewhere in the memory.
 
-PGG and gpg.el enables passphrase caching by default.
+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.