From 489df1c47cad55da2e9071a98a403ca9389758ba Mon Sep 17 00:00:00 2001
From: emergent-reasons <emergentreasons@gmail.com>
Date: Wed, 8 May 2019 01:17:33 +0900
Subject: [PATCH] clarify transaction requirements

---
 SPECIFICATION.md | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/SPECIFICATION.md b/SPECIFICATION.md
index 0a9eb7f..c0bcfe9 100644
--- a/SPECIFICATION.md
+++ b/SPECIFICATION.md
@@ -1,5 +1,7 @@
 # CashShuffle specification
 
+This specification is for version 300 of the CashShuffle protocol.
+
 ## Communication
 
 - The server should support TLSv1.2 between the client and server.
@@ -8,6 +10,15 @@
   2. 4-bytes specifying the length of the message in bytes in big endian order.
   3. The protobuf payload.
 
+## Shuffle transaction
+
+In order to avoid client identification and ensure compatibility:
+
+- Transactions should use only ECDSA signing.
+- Transactions should use `nLockTime = 0`.
+- Transactions should use `nVersion = 1`.
+- Each input should use `nSequence = 0xfffffffe`.
+
 ## Protobuf payload
 
 - The client and server should communicate according to the [protobuf specification](https://github.com/Electron-Cash/Electron-Cash/blob/master/plugins/shuffle/protobuf/message.proto) for messages.