diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -1,4 +1,17 @@
-dmcryptfile
-===========
+Encrypts/decrypts file in dm-crypt compatible way, using kernel crypto API.
+Copyright (c) 2013 Maxim Radugin.
+
+Usage: dmcryptfile <arguments>
+
+This utility is designed to encrypt disk/partition image files in userspace
+without root priviledges and without using device mapper and cryptsetup.
+Currently supports only plain mode, no LUKS support!
+Backend code is taken from cryptsetup.
+Input key size should be of desired cipher key size.
+Key is passed directly to the cipher algorithm, no hashing or any other
+processing is performed. It is up to the user to provide strong key.
+For available ciphers, chain modes and key sizes check /proc/crypto.
+Only plain IV mode is supported.
+Input file size must be multiple of sector size i.e. 512 bytes.
+If input file is not multiple of sector size, output will be truncated.
 
-Encrypts/decrypts file in plain dm-crypt compatible way, using kernel crypto API.
diff --git a/crypto_backend.h b/crypto_backend.h
old mode 100755
new mode 100644
diff --git a/crypto_kernel.c b/crypto_kernel.c
old mode 100755
new mode 100644
diff --git a/dmcryptfile.c b/dmcryptfile.c
old mode 100755
new mode 100644