docs/PROTOCOL.md

@@ -97,22 +97,20 @@ All protocol messages use a binary format with the following structure:
 - **Format**:
 ```json
 {
-  "id": "challenge_unique_id",
   "timestamp": 1640995200,
   "difficulty": 4,
-  "resource": "192.168.1.100:8080",
+  "resource": "quotes",
   "random": "a1b2c3d4e5f6",
   "hmac": "base64url_encoded_signature"
 }
 ```
 
 **Field Descriptions**:
-- **id**: Unique identifier for this challenge
 - **timestamp**: Unix timestamp when challenge was created
 - **difficulty**: Number of leading zero bits required in solution hash
-- **resource**: Server resource identifier (typically IP:port)
+- **resource**: Server resource identifier (e.g., "quotes")
 - **random**: Random hex string for challenge uniqueness
-- **hmac**: HMAC-SHA256 signature of canonical challenge fields
+- **hmac**: HMAC-SHA256 signature of canonical challenge fields (also serves as unique identifier)
 
 **Security Notes**:
 - Server is **stateless**: no need to store challenges locally
@@ -126,10 +124,9 @@ All protocol messages use a binary format with the following structure:
 ```json
 {
   "challenge": {
-    "id": "challenge_unique_id",
     "timestamp": 1640995200,
     "difficulty": 4,
-    "resource": "192.168.1.100:8080",
+    "resource": "quotes",
     "random": "a1b2c3d4e5f6",
     "hmac": "base64url_encoded_signature"
   },