update rpuzzle

docs/rpuzzle.rst

@@ -4,24 +4,28 @@ R-Puzzle
 
 In R-puzzle, an ephemeral key ``k`` is never revealed. Instead ``r``, the x coordinate of its corresponding public key, 
 is revealed and from ``r`` along with the signature, the knowledge of ``k`` can be proved using existing ``checkSig``.
-
-One crucial step in R-Puzzle is to extract ``r`` from `DER`_ encoded signature. The following is much easier than what is presented in the `R-Puzzle`_ talk.
+More information can be found in the `R-Puzzle`_ talk.
 
 .. code-block:: solidity
 
     contract RPuzzle {
-        Sig s;  // s = b'3045022100948c67a95f856ae875a48a2d104df9d232189897a811178a715617d4b090a7e90220616f6ced5ab219fe1bfcf9802994b3ce72afbb2db0c4b653a74c9f03fb99323f01'
+        Ripemd160 rhash;
+
+        constructor(Ripemd160 rhash) {
+            this.rhash = rhash;
+        }
 
-        function getSigR(Sig sig): bytes {
-            bytes lenBytes = sig[3:4];
+        function getSigR(Sig sigr): bytes {
+            bytes lenBytes = sigr[3:4];
             int len = unpack(lenBytes);
-            bytes r = sig[4:4+len];
+            bytes r = sigr[4:4+len];
             return r;
         }
 
-        // r = b'00948c67a95f856ae875a48a2d104df9d232189897a811178a715617d4b090a7e9'
-        public function unlock(bytes r) {
-            require(r == this.getSigR(this.s));
+        public function unlock(Sig sig, PubKey pubKey, Sig sigr) {
+            require(this.rhash == hash160(this.getSigR(sigr)));
+            require(checkSig(sigr, pubKey));
+            require(checkSig(sig, pubKey));
         }
     }