diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -1 +1,17 @@
-VTUN fork.
\ No newline at end of file
+This is a fork of [VTUN](http://vtun.sourceforge.net/), with the
+following changes:
+
+* OpenSSL was replaced by Libsodium (this currently requires the
+[aes256gcm](https://github.com/jedisct1/libsodium/tree/aes256gcm)
+branch).
+
+* Unauthenticated encryption schemes were replaced with aesni and
+pclmulqdq-accelerated AES256-GCM.
+
+* Protection against replay attacks was added.
+
+* More secure key derivation and initial handshake.
+
+* Passwords are not kept in memory.
+
+* Guarded memory allocations for secrets.