readme: update example

Make it more clear that signing should be done on
the hash of a message rather than on a message directly.

README.md

@@ -55,35 +55,46 @@ var ec = new EC('secp256k1');
 // Generate keys
 var key = ec.genKeyPair();
 
-// Sign message (must be an array, or it'll be treated as a hex sequence)
+// Sign the message's hash (input must be an array, or a hex-string)
-var msg = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ];
+var msgHash = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ];
-var signature = key.sign(msg);
+var signature = key.sign(msgHash);
 
 // Export DER encoded signature in Array
 var derSign = signature.toDER();
 
 // Verify signature
-console.log(key.verify(msg, derSign));
+console.log(key.verify(msgHash, derSign));
 
 // CHECK WITH NO PRIVATE KEY
 
-// Public key as '04 + x + y'
+var pubPoint = key.getPublic();
-var pub = '04bb1fa3...';
+var x = pubPoint.getX();
+var y = pubPoint.getY();
 
-// Signature MUST be either:
+// Public Key MUST be either:
-// 1) hex-string of DER-encoded signature; or
+// 1) '04' + hex string of x + hex string of y; or
-// 2) DER-encoded signature as buffer; or
+// 2) object with two hex string properties (x and y); or
-// 3) object with two hex-string properties (r and s)
+// 3) object with two buffer properties (x and y)
-
+var pub = pubPoint.encode('hex');                                 // case 1
-var signature = 'b102ac...'; // case 1
+var pub = { x: x.toString('hex'), y: y.toString('hex') };         // case 2
-var signature = new Buffer('...'); // case 2
+var pub = { x: x.toBuffer(), y: y.toBuffer() };                   // case 3
-var signature = { r: 'b1fc...', s: '9c42...' }; // case 3
+var pub = { x: x.toArrayLike(Buffer), y: y.toArrayLike(Buffer) }; // case 3
 
 // Import public key
 var key = ec.keyFromPublic(pub, 'hex');
 
+// Signature MUST be either:
+// 1) DER-encoded signature as hex-string; or
+// 2) DER-encoded signature as buffer; or
+// 3) object with two hex-string properties (r and s); or
+// 4) object with two buffer properties (r and s)
+
+var signature = '3046022100...'; // case 1
+var signature = new Buffer('...'); // case 2
+var signature = { r: 'b1fc...', s: '9c42...' }; // case 3
+
 // Verify signature
-console.log(key.verify(msg, signature));
+console.log(key.verify(msgHash, signature));
 ```
 
 ### EdDSA
@@ -98,12 +109,12 @@ var ec = new EdDSA('ed25519');
 // Create key pair from secret
 var key = ec.keyFromSecret('693e3c...'); // hex string, array or Buffer
 
-// Sign message (must be an array, or it'll be treated as a hex sequence)
+// Sign the message's hash (input must be an array, or a hex-string)
-var msg = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ];
+var msgHash = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ];
-var signature = key.sign(msg).toHex();
+var signature = key.sign(msgHash).toHex();
 
 // Verify signature
-console.log(key.verify(msg, signature));
+console.log(key.verify(msgHash, signature));
 
 // CHECK WITH NO PRIVATE KEY
 
@@ -113,7 +124,7 @@ var key = ec.keyFromPublic(pub, 'hex');
 
 // Verify signature
 var signature = '70bed1...';
-console.log(key.verify(msg, signature));
+console.log(key.verify(msgHash, signature));
 ```
 
 ### ECDH