diff --git a/ChangeLog b/ChangeLog
index 69e8ffb0c6..5e4b03f9f1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+Thu May 17 07:16:38 2001  Akinori MUSHA  <knu@iDaemons.org>
+
+	* ext/sha1/sha1.txt.jp: add the Japanese version derived from
+	ext/md5/md5.txt.jp.
+
+	* ext/sha1/sha1.txt: revise the copyright info and reduce the
+	difference from ext/md5/md5.txt.
+
+	* ext/md5/md5.txt: reduce the difference from ext/sha1/sha1.txt.
+
 Thu May 17 07:11:35 2001  Akinori MUSHA  <knu@iDaemons.org>
 
 	* ext/sha1/extconf.rb, ext/sha1/sha1.c: use WORDS_BIGENDIAN to
diff --git a/ext/md5/md5.txt b/ext/md5/md5.txt
index 211a5302b5..a3c50ff407 100644
--- a/ext/md5/md5.txt
+++ b/ext/md5/md5.txt
@@ -5,7 +5,7 @@
 A class to implement MD5 Message-Digest Algorithm by RSA Data
 Security, Inc., described in RFC1321.
 
-SuperClass: Object
+Superclass: Object
 
 Class Methods:
 
diff --git a/ext/sha1/sha1.txt b/ext/sha1/sha1.txt
index 24bf0d4244..dd13993d53 100644
--- a/ext/sha1/sha1.txt
+++ b/ext/sha1/sha1.txt
@@ -1,33 +1,36 @@
-Class SHA1
+.\" sha1.doc -  -*- Indented-Text -*- created at: Thu Mat 17 06:51:50 JST 2001
 
-	A class to implement the SHA1 Secure Hash Algorithm by NIST (the US'
-	National Institute of Standards and Technology), described in FIPS PUB
-	180-1.
+** SHA1(Class)
+
+A class to implement the SHA1 Secure Hash Algorithm by NIST (the US'
+National Institute of Standards and Technology), described in FIPS PUB
+180-1.
 
 Superclass: Object
 
 Class Methods:
 
-    new([str])
-    sha1([str])
+   new([str])
+   sha1([str])
 
 	Creates a new SHA1 object.  If a string argument is given, it
         is added to the object. (see update.)
 
 Methods:
 
-    clone
+   clone
 
 	Copies the SHA1 object.
 
-    digest
+   digest
 
-	Returns the SHA1 hash of the added strings as a string of 20 bytes.
+	Returns the SHA1 hash of the added strings as a string of 20
+	bytes.
 
-    hexdigest
+   hexdigest
 
 	Returns the SHA1 hash of the added strings as a string of 40
-	hexadecimal digits. This method is equal to:
+	hexadecimal digits.  This method is equal to:
 
 	def hexdigest
 	  ret = ''
@@ -35,8 +38,8 @@ Methods:
 	  ret
 	end
 
-    update(str)
-    << str
+   update(str)
+   << str
 
 	Updates the SHA1 object with string str.  Repeated calls are
 	equivalent to a single call with the concatenation of all the
@@ -45,6 +48,9 @@ Methods:
 
 Copyright:
 
-	README and sha1-ruby.c are derived from the Ruby source and so fall
-	under the same license as Ruby.  The rest of this package is in the
-	public domain.
+	sha1.c is in the public domain.
+
+-------------------------------------------------------
+Local variables:
+fill-column: 70
+end:
diff --git a/ext/sha1/sha1.txt.jp b/ext/sha1/sha1.txt.jp
new file mode 100644
index 0000000000..ca6013ca47
--- /dev/null
+++ b/ext/sha1/sha1.txt.jp
@@ -0,0 +1,57 @@
+.\" sha1.doc -  -*- Indented-Text -*- created at: Thu Mat 17 06:51:50 JST 2001
+
+** SHA1(クラス)
+
+FIPS PUB 180-1に記述されているNIST (the US' National Institute of
+Standards and Technology) の SHA1 Secure Hash Algorithm Algorithmを実装
+するクラス。
+
+SuperClass: Object
+
+Class Methods:
+
+   new([str])
+   sha1([str])
+
+        新しいSHA1オブジェクトを生成する．文字列引数が与えられるとそれ
+        を追加する(see update)。
+
+Methods:
+
+   clone
+
+	SHA1オブジェクトの複製を作る。
+
+   digest
+
+        今までに追加した文字列に対するハッシュ値を20バイト長の文字列で
+        返す。
+
+   hexdigest
+
+        今までに追加した文字列に対するハッシュ値を、ASCIIコードを使って
+        16進数の列を示す'18e40e1401eef67e1ae69efab09afb71f87ffb81'のよう
+        な40文字の文字列にエンコードして返す。Rubyで書くと以下と同じ。
+
+	def hexdigest
+  	  ret = ''
+	  digest.each_byte {|i| ret << sprintf('%02x', i) }
+	  ret
+	end
+
+   update(str)
+   << str
+
+        SHA1オブジェクトに文字列を追加する。複数回updateを呼ぶことは文
+        字列を連結してupdateを呼ぶことと等しい。すなわち m.update(a);
+	m.update(b) は m.update(a+b) と、 m << a << b は m << a+b と
+	それぞれ等価である。
+
+Copyright:
+
+	sha1.c はパブリックドメインである。
+
+-------------------------------------------------------
+Local variables:
+fill-column: 70
+end: