diff --git a/index.html b/index.html
index 691dbd5b..87ec3506 100644
--- a/index.html
+++ b/index.html
@@ -582,12 +582,27 @@ <h2>New HD Address <small>making bip32 even easier</small></h2>
 							</span>
 						</div>
 
+						<label>Seed (WIF)</label>
+						<div class="input-group">
+							<input id="newHDseed" type="text" class="form-control" value="" readonly>
+							<span class="input-group-btn">
+								<button class="deriveHDbtn btn btn-default" type="button"><span title="Derive from key" class="glyphicon glyphicon-chevron-right"></span></button>
+							</span>
+						</div>
+
 						<h3>Address Options</h3>
 						<p>You can use the advanced options below to generate different kinds of master addresses.</p>
 						
 						<div class="checkbox">
 							<label><input type="checkbox" id="newHDBrainwallet" class="checkbox-inline"> Custom Seed or Brain Wallet</label>
-							<input type="text" class="form-control hidden" id="HDBrainwallet">
+							<div class="hidden" id="HDBrainwalletInput">
+								<input type="text" class="form-control" id="HDBrainwallet">
+								<span class="text-muted">
+									Number of HMAC SHA-256 iterations for seed generation, higher value mean's also longer calculation
+									(use value 0 to calculate just SHA-256, like in previous coinb.in versions):
+									<input type="text" class="form-control" id="HDBrainwalletIters" value="50000" size="10">
+								</span>
+							</div>
 						</div>
 
 						<input type="button" class="btn btn-primary" value="Generate" id="newHDKeysBtn">
diff --git a/js/coin.js b/js/coin.js
index d8f5388f..b58ad906 100644
--- a/js/coin.js
+++ b/js/coin.js
@@ -608,6 +608,7 @@
 				r.parent_fingerprint = bytes.slice(5, 9);
 				r.child_index = coinjs.uint(bytes.slice(9, 13), 4);
  				r.chain_code = bytes.slice(13, 45);
+				r.seed_wif = '';
 				r.key_bytes = bytes.slice(45, 78);
 
 				var c = coinjs.compressed; // get current default
@@ -742,8 +743,23 @@
 		}
 
 		// make a master hd xprv/xpub
-		r.master = function(pass) {
-			var seed = (pass) ? Crypto.SHA256(pass) : coinjs.newPrivkey();
+		r.master = function(pass, iters) {
+			if (pass) {
+				var seed_iters = (iters) ? Math.abs(iters * 1) : 0;
+				if (seed_iters == 0) {
+					var seed = Crypto.SHA256(pass);
+				} else {
+					var seed = Crypto.util.hexToBytes("0000000000000000000000000000000000000000000000000000000000000000");
+					for (var i = 0; i < seed_iters; i++) {
+						seed = Crypto.HMAC(Crypto.SHA256, seed, pass, { asBytes: true });
+					}
+					seed = Crypto.util.bytesToHex(seed);
+				}
+			} else {
+				var seed = coinjs.newPrivkey();
+			}
+
+			var seed_wif = coinjs.privkey2wif(seed);
 			var hasher = new jsSHA(seed, 'HEX');
 			var I = hasher.getHMAC("Bitcoin seed", "TEXT", "SHA-512", "HEX");
 
@@ -755,6 +771,7 @@
 				'parent_fingerprint':[0,0,0,0],
 				'child_index':0,
 				'chain_code':chain,
+				'seed_wif':seed_wif,
 				'privkey':I.slice(0, 64),
 				'pubkey':coinjs.newPubkey(I.slice(0, 64))});
 		}
@@ -799,6 +816,8 @@
 				var ret = pub.concat(checksum);
 				o.pubkey = coinjs.base58encode(ret);
 			}
+
+			o.seed_wif = data.seed_wif;
 			return o;
 		}
 
diff --git a/js/coinbin.js b/js/coinbin.js
index afc98f17..a1ba84ad 100644
--- a/js/coinbin.js
+++ b/js/coinbin.js
@@ -570,18 +570,20 @@ $(document).ready(function() {
 	$("#newHDKeysBtn").click(function(){
 		coinjs.compressed = true;
 		var s = ($("#newHDBrainwallet").is(":checked")) ? $("#HDBrainwallet").val() : null;
+		var siters = ($("#newHDBrainwallet").is(":checked")) ? $("#HDBrainwalletIters").val()*1 : null;
 		var hd = coinjs.hd();
-		var pair = hd.master(s);
+		var pair = hd.master(s, siters);
 		$("#newHDxpub").val(pair.pubkey);
 		$("#newHDxprv").val(pair.privkey);
+		$("#newHDseed").val(pair.seed_wif);
 
 	});
 
 	$("#newHDBrainwallet").click(function(){
 		if($(this).is(":checked")){
-			$("#HDBrainwallet").removeClass("hidden");
+			$("#HDBrainwalletInput").removeClass("hidden");
 		} else {
-			$("#HDBrainwallet").addClass("hidden");
+			$("#HDBrainwalletInput").addClass("hidden");
 		}
 	});
 
@@ -1681,6 +1683,7 @@ $(document).ready(function() {
 			if(hex == hex_cmp_prv || hex == hex_cmp_pub){
 				var hd = coinjs.hd(s);
 				$("#verifyHDaddress .hdKey").html(s);
+				$("#verifyHDaddress .seed_wif").val(hd.seed_wif);
 				$("#verifyHDaddress .chain_code").val(Crypto.util.bytesToHex(hd.chain_code));
 				$("#verifyHDaddress .depth").val(hd.depth);
 				$("#verifyHDaddress .version").val('0x'+(hd.version).toString(16));