diff --git a/lib/bcoin/hd.js b/lib/bcoin/hd.js
index f8ab2ffe..b0e6a73d 100644
--- a/lib/bcoin/hd.js
+++ b/lib/bcoin/hd.js
@@ -152,8 +152,6 @@ function HDPrivateKey(options) {
     data = options;
   }
 
-  this.master = options.master || this;
-
   data = this._normalize(data, network.prefixes.xprivkey);
 
   this.data = data;
@@ -347,7 +345,6 @@ HDPrivateKey.prototype.derive = function derive(index, hardened) {
 
   return new HDPrivateKey({
     version: null,
-    master: this.master,
     depth: new bn(this.depth).toNumber() + 1,
     parentFingerPrint: this.fingerPrint,
     childIndex: index,
diff --git a/lib/bcoin/miner.js b/lib/bcoin/miner.js
index 0d1f8036..b8f9e9dd 100644
--- a/lib/bcoin/miner.js
+++ b/lib/bcoin/miner.js
@@ -156,7 +156,7 @@ Miner.prototype.addTX = function addTX(tx) {
   if (tx.height !== -1)
     return;
 
-  if (!tx.verify())
+  if (!tx.verify(null, true))
     return;
 
   if (tx.isCoinbase())
diff --git a/lib/bcoin/script.js b/lib/bcoin/script.js
index cc80a1a9..206ef01d 100644
--- a/lib/bcoin/script.js
+++ b/lib/bcoin/script.js
@@ -248,7 +248,7 @@ script.execute = function execute(s, stack, tx, index, flags, recurse) {
   var v, v1, v2, v3, v4;
   var n, n1, n2, n3;
   var res;
-  var pub, sig, type, subscript, hash;
+  var key, sig, type, subscript, hash;
   var keys, i, j, key, m;
   var succ;
   var lock, threshold;
@@ -679,11 +679,11 @@ script.execute = function execute(s, stack, tx, index, flags, recurse) {
         if (!tx || stack.length < 2)
           return false;
 
-        pub = stack.pop();
+        key = stack.pop();
         sig = stack.pop();
         type = sig[sig.length - 1];
 
-        if (!constants.hashTypeByVal[type & 0x1f])
+        if (!script.isKey(key))
           return false;
 
         if (flags.strictder !== false) {
@@ -694,10 +694,13 @@ script.execute = function execute(s, stack, tx, index, flags, recurse) {
             return false;
         }
 
+        if (!constants.hashTypeByVal[type & 0x1f])
+          return false;
+
         subscript = script.subscript(s, lastSep);
         hash = tx.subscriptHash(index, subscript, type);
 
-        res = script.verify(hash, sig.slice(0, -1), pub);
+        res = script.verify(hash, sig.slice(0, -1), key);
         if (o === 'checksigverify') {
           if (!res)
             return false;
@@ -723,7 +726,7 @@ script.execute = function execute(s, stack, tx, index, flags, recurse) {
         keys = [];
         for (i = 0; i < n; i++) {
           key = stack.pop();
-          if (!(33 <= key.length && key.length <= 65))
+          if (!script.isKey(key))
             return false;
 
           keys.push(key);
@@ -745,9 +748,6 @@ script.execute = function execute(s, stack, tx, index, flags, recurse) {
           sig = stack.pop();
           type = sig[sig.length - 1];
 
-          if (!constants.hashTypeByVal[type & 0x1f])
-            return false;
-
           if (flags.strictder !== false) {
             if (!script.isValidSig(sig))
               return false;
@@ -756,6 +756,9 @@ script.execute = function execute(s, stack, tx, index, flags, recurse) {
               return false;
           }
 
+          if (!constants.hashTypeByVal[type & 0x1f])
+            return false;
+
           hash = tx.subscriptHash(index, subscript, type);
 
           res = false;
@@ -1123,11 +1126,12 @@ script.isPubkeyInput = function isPubkeyInput(s, key, tx, i) {
   if (s.length !== 1 || !Array.isArray(s[0]))
     return false;
 
-  // res = script.isValidSig(s[0]);
-  res = 9 <= s[0].length && s[0].length <= 73;
-  if (!res)
+  if (!script.isSig(s[0]))
     return false;
 
+  // Execute the script against our key's
+  // checksig script to see if this is our input.
+  // This will only work if the script verifies.
   if (key)
     return script.exec(s, [key, 'checksig'], tx, i);
 
@@ -1135,20 +1139,15 @@ script.isPubkeyInput = function isPubkeyInput(s, key, tx, i) {
 };
 
 script.isPubkeyhashInput = function isPubkeyhashInput(s, key) {
-  var res;
-
   s = script.subscript(s);
 
   if (s.length !== 2 || !Array.isArray(s[0]) || !Array.isArray(s[1]))
     return false;
 
-  // res = script.isValidSig(s[0])
-  //   && 33 <= s[1].length && s[1].length <= 65;
+  if (!script.isSig(s[0]))
+    return false;
 
-  res = 9 <= s[0].length && s[0].length <= 73
-    && 33 <= s[1].length && s[1].length <= 65;
-
-  if (!res)
+  if (!script.isKey(s[1]))
     return false;
 
   if (key)
@@ -1160,7 +1159,8 @@ script.isPubkeyhashInput = function isPubkeyhashInput(s, key) {
 script.isMultisigInput = function isMultisigInput(s, pubs, tx, i) {
   var i, res, o;
 
-  // We need to rule out scripthash because it may look like multisig
+  // We need to rule out scripthash
+  // because it may look like multisig
   if (script.isScripthashInput(s))
     return false;
 
@@ -1173,12 +1173,13 @@ script.isMultisigInput = function isMultisigInput(s, pubs, tx, i) {
     return false;
 
   for (i = 1; i < s.length; i++) {
-    // res = script.isValidSig(s[i]);
-    res = Array.isArray(s[i]) && 9 <= s[i].length && s[i].length <= 73;
-    if (!res)
+    if (!script.isSig(s[i]))
       return false;
   }
 
+  // Execute the script against our pubkeys'
+  // redeem script to see if this is our input.
+  // This will only work if the script verifies.
   if (pubs && pubs.length >= 2) {
     o = script.redeem(pubs, 2, pubs.length);
     return script.exec(s, o, tx, i);
@@ -1199,9 +1200,7 @@ script.isScripthashInput = function isScripthashInput(s, redeem) {
     return false;
 
   for (i = 1; i < s.length - 1; i++) {
-    // res = script.isValidSig(s[i]);
-    res = Array.isArray(s[i]) && 9 <= s[i].length && s[i].length <= 73;
-    if (!res)
+    if (!script.isSig(s[i]))
       return false;
   }
 
@@ -1320,6 +1319,13 @@ script.isCoinbase = function isCoinbase(s, block, strict) {
   return coinbase;
 };
 
+script.isKey = function isKey(key) {
+  if (!utils.isBuffer(key))
+    return false;
+
+  return key.length >= 33 && key.length <= 65;
+};
+
 script.isSig = function isSig(sig, allowZero) {
   if (!utils.isBuffer(sig))
     return false;
@@ -1327,7 +1333,7 @@ script.isSig = function isSig(sig, allowZero) {
   if (allowZero && sig.length === 0)
     return true;
 
-  return 9 <= sig.length && sig.length <= 73;
+  return sig.length >= 9 && sig.length <= 73;
 };
 
 // https://github.com/bitcoin/bips/blob/master/bip-0066.mediawiki
diff --git a/lib/bcoin/tx-pool.js b/lib/bcoin/tx-pool.js
index 80ede089..58a0602b 100644
--- a/lib/bcoin/tx-pool.js
+++ b/lib/bcoin/tx-pool.js
@@ -96,6 +96,9 @@ TXPool.prototype.add = function add(tx, noWrite) {
     key = input.out.hash + '/' + input.out.index;
     unspent = this._unspent[key];
 
+    if (!input.out.tx && this._all[input.out.hash])
+      input.out.tx = this._all[input.out.hash];
+
     if (unspent) {
       // Add TX to inputs and spend money
       index = tx._inputIndex(unspent.tx.hash('hex'), unspent.index);
@@ -121,7 +124,7 @@ TXPool.prototype.add = function add(tx, noWrite) {
     // we could in theory use ownInput here (and down below)
     // instead.
     // if (this._wallet.ownInput(input.out.tx, input.out.index))
-    if (tx.inputs[i].out.tx) {
+    if (input.out.tx) {
       if (!this._wallet.ownOutput(input.out.tx, input.out.index))
         continue;
     }
diff --git a/lib/bcoin/tx.js b/lib/bcoin/tx.js
index f700a445..c1621481 100644
--- a/lib/bcoin/tx.js
+++ b/lib/bcoin/tx.js
@@ -157,10 +157,18 @@ TX.prototype._inputIndex = function _inputIndex(hash, index) {
 };
 
 // Build the scriptSigs for inputs, excluding the signatures
-TX.prototype.scriptInput = function scriptInput(input, pub) {
+TX.prototype.scriptInput = function scriptInput(index, pub) {
+  var input, s, n, i, redeem;
+
+  if (typeof index !== 'number')
+    index = this.inputs.indexOf(index);
+
+  // Get the input
+  input = this.inputs[index];
+  assert(input);
+
   // Get the previous output's subscript
-  var s = input.out.tx.getSubscript(input.out.index);
-  var n, i, redeem;
+  s = input.out.tx.getSubscript(input.out.index);
 
   // Already has a script template (at least)
   if (input.script.length)
@@ -218,16 +226,23 @@ TX.prototype.scriptInput = function scriptInput(input, pub) {
 };
 
 // Sign the now-built scriptSigs
-TX.prototype.signInput = function signInput(input, key, type) {
-  var s, hash, signature;
+TX.prototype.signInput = function signInput(index, key, type) {
+  var input, s, hash, signature;
   var len, redeem, m, keys, pub, pubn, ki, totalSigs, i;
 
+  if (typeof index !== 'number')
+    index = this.inputs.indexOf(index);
+
   if (!type)
     type = 'all';
 
   if (typeof type === 'string')
     type = constants.hashType[type];
 
+  // Get the input
+  input = this.inputs[index];
+  assert(input);
+
   // Get the previous output's subscript
   s = input.out.tx.getSubscript(input.out.index);
 
@@ -239,7 +254,7 @@ TX.prototype.signInput = function signInput(input, key, type) {
   }
 
   // Get the hash of the current tx, minus the other inputs, plus the sighash.
-  hash = this.subscriptHash(this.inputs.indexOf(input), redeem, type);
+  hash = this.subscriptHash(index, redeem, type);
 
   // Sign the transaction with our one input
   signature = bcoin.ecdsa.sign(hash, key.priv).toDER();
@@ -324,23 +339,32 @@ TX.prototype.signInput = function signInput(input, key, type) {
 };
 
 // Build the scriptSig and sign it
-TX.prototype.scriptSig = function scriptSig(input, key, pub, type) {
+TX.prototype.scriptSig = function scriptSig(index, key, pub, type) {
+  var input;
+
   if (!utils.isBuffer(pub)) {
     type = pub;
     pub = key.getPublic(true, 'array');
   }
 
+  if (typeof index !== 'number')
+    index = this.inputs.indexOf(index);
+
+  // Get the input
+  input = this.inputs[index];
+  assert(input);
+
   // Build script for input
-  this.scriptInput(input, pub);
+  this.scriptInput(index, pub);
 
   // Sign input
-  this.signInput(input, key, type);
+  this.signInput(index, key, type);
 
   return input.script;
 };
 
 TX.prototype.output = function output(obj, value) {
-  var options;
+  var options, output;
 
   if (obj instanceof bcoin.wallet)
     obj = obj.getAddress();
@@ -354,7 +378,7 @@ TX.prototype.output = function output(obj, value) {
     options = obj;
   }
 
-  var output = bcoin.output({
+  output = bcoin.output({
     tx: this,
     value: options.value,
     script: options.script
@@ -362,7 +386,7 @@ TX.prototype.output = function output(obj, value) {
 
   this.outputs.push(output);
 
-  this.scriptOutput(output, options);
+  this.scriptOutput(this.outputs.length - 1, options);
 
   return this;
 };
@@ -370,11 +394,19 @@ TX.prototype.output = function output(obj, value) {
 // compat
 TX.prototype.out = TX.prototype.output;
 
-TX.prototype.scriptOutput = function scriptOutput(output, options) {
-  var script = output.script;
-  var keys, m, n, hash, locktime, flags;
+TX.prototype.scriptOutput = function scriptOutput(index, options) {
+  var output, script, keys, m, n, hash, locktime, flags;
 
-  options = options || output;
+  if (typeof index !== 'number')
+    index = this.outputs.indexOf(index);
+
+  output = this.outputs[index];
+  assert(output);
+
+  if (!options)
+    options = output;
+
+  script = output.script;
 
   if (options instanceof bcoin.output) {
     options = Object.keys(options).reduce(function(out, key) {
@@ -499,6 +531,9 @@ TX.prototype.subscriptHash = function subscriptHash(index, s, type) {
   var copy = this.clone();
   var verifyStr, hash;
 
+  if (typeof index !== 'number')
+    index = this.inputs.indexOf(index);
+
   if (typeof type === 'string')
     type = constants.hashType[type];
 
@@ -508,7 +543,7 @@ TX.prototype.subscriptHash = function subscriptHash(index, s, type) {
     return constants.oneHash.slice();
 
   copy.inputs.forEach(function(input, i) {
-    input.script = index === i ? s : [];
+    input.script = i === index ? s : [];
   });
 
   if ((type & 0x1f) === constants.hashType.all) {
@@ -564,12 +599,18 @@ TX.prototype.verify = function verify(index, force, flags) {
   return this.inputs.every(function(input, i) {
     var stack, prev, push, res, redeem;
 
-    if (index !== undefined && index !== i)
+    if (index != null && index !== i)
       return true;
 
     if (!input.out.tx)
       return false;
 
+    assert.equal(input.out.tx.hash('hex'), input.out.hash);
+
+    // Transaction cannot reference itself
+    if (input.out.tx.hash('hex') === this.hash('hex'))
+      return false;
+
     assert(input.out.tx.outputs.length > input.out.index);
 
     stack = [];
diff --git a/lib/bcoin/wallet.js b/lib/bcoin/wallet.js
index 832cb093..08de94bf 100644
--- a/lib/bcoin/wallet.js
+++ b/lib/bcoin/wallet.js
@@ -125,11 +125,6 @@ Wallet.prototype._init = function init() {
   });
 };
 
-// If we want to use p2sh addresses for the prefix:
-// Wallet.prototype.__defineGetter__('prefix', function() {
-//   return 'bt/' + this.getFullAddress() + '/';
-// });
-
 Wallet.prototype.multisig = function multisig(options) {
   var pub = this.getOwnPublicKey();
 
@@ -364,7 +359,7 @@ Wallet.prototype.ownOutput = function ownOutput(tx, index) {
   var outputs = tx.outputs.filter(function(output, i) {
     var s = output.script;
 
-    if (index !== undefined && index !== i)
+    if (index != null && index !== i)
       return false;
 
     if (bcoin.script.isPubkey(s, key))
@@ -398,7 +393,10 @@ Wallet.prototype.ownInput = function ownInput(tx, index) {
   var inputs = tx.inputs.filter(function(input, i) {
     var s;
 
-    if (index !== undefined && index !== i)
+    if (!input.out.tx && this.tx._all[input.out.hash])
+      input.out.tx = this.tx._all[input.out.hash];
+
+    if (index != null && index !== i)
       return false;
 
     // if (bcoin.script.isPubkeyInput(input.script, key, tx, i))
@@ -416,7 +414,7 @@ Wallet.prototype.ownInput = function ownInput(tx, index) {
     if (!input.out.tx)
       return false;
 
-    s = input.out.tx.outputs[input.out.index].script;
+    s = input.out.tx.getSubscript(input.out.index);
 
     if (bcoin.script.isPubkey(s, key))
       return true;
@@ -456,12 +454,15 @@ Wallet.prototype.scriptInputs = function scriptInputs(tx, inputs) {
 
   inputs = inputs || tx.inputs;
 
-  inputs = inputs.filter(function(input) {
+  inputs = inputs.filter(function(input, i) {
+    if (!input.out.tx && this.tx._all[input.out.hash])
+      input.out.tx = this.tx._all[input.out.hash];
+
     // Filter inputs that this wallet own
     if (!input.out.tx || !this.ownOutput(input.out.tx))
       return false;
 
-    tx.scriptInput(input, pub);
+    tx.scriptInput(i, pub);
 
     return true;
   }, this);
@@ -477,11 +478,14 @@ Wallet.prototype.signInputs = function signInputs(tx, type, inputs) {
 
   inputs = inputs || tx.inputs;
 
-  inputs = inputs.filter(function(input) {
+  inputs = inputs.filter(function(input, i) {
+    if (!input.out.tx && this.tx._all[input.out.hash])
+      input.out.tx = this.tx._all[input.out.hash];
+
     if (!input.out.tx || !this.ownOutput(input.out.tx))
       return false;
 
-    tx.signInput(input, key, type);
+    tx.signInput(i, key, type);
 
     return true;
   }, this);
@@ -499,12 +503,15 @@ Wallet.prototype.sign = function sign(tx, type, inputs) {
   inputs = inputs || tx.inputs;
 
   // Add signature script to each input
-  inputs = inputs.filter(function(input) {
+  inputs = inputs.filter(function(input, i) {
+    if (!input.out.tx && this.tx._all[input.out.hash])
+      input.out.tx = this.tx._all[input.out.hash];
+
     // Filter inputs that this wallet own
     if (!input.out.tx || !this.ownOutput(input.out.tx))
       return false;
 
-    tx.scriptSig(input, key, pub, type);
+    tx.scriptSig(i, key, pub, type);
 
     return true;
   }, this);
@@ -591,7 +598,7 @@ Wallet.prototype.toAddress = function toAddress() {
 
 Wallet.prototype.toJSON = function toJSON(encrypt) {
   return {
-    v: 1,
+    v: 2,
     type: 'wallet',
     network: network.type,
     encrypted: encrypt ? true : false,
@@ -603,21 +610,9 @@ Wallet.prototype.toJSON = function toJSON(encrypt) {
       ? encrypt(this.getPrivateKey('base58'))
       : this.getPrivateKey('base58'),
     tx: this.tx.toJSON(),
-    ntx: this.tx.all().length,
-    hd: this.hd ? {
-      seed: this.hd.seed ? {
-        mnemonic: encrypt
-          ? encrypt(this.hd.seed.mnemonic)
-          : this.hd.seed.mnemonic,
-        passphrase: encrypt
-          ? encrypt(this.hd.seed.passphrase)
-          : this.hd.seed.passphrase
-      } : undefined,
-      depth: new bn(this.hd.data.depth).toNumber(),
-      parentFingerPrint: utils.toHex(this.hd.data.parentFingerPrint),
-      childIndex: new bn(this.hd.data.childIndex).toNumber(),
-      chainCode: utils.toHex(this.hd.data.chainCode)
-    } : undefined,
+    xprivkey: this.hd
+      ? (encrypt ? encrypt(this.hd.xprivkey) : this.hd.xprivkey)
+      : null,
     multisig: this.n > 1 ? {
       type: this.type,
       keys: this.keys.map(utils.toBase58),
@@ -628,9 +623,13 @@ Wallet.prototype.toJSON = function toJSON(encrypt) {
 };
 
 Wallet.fromJSON = function fromJSON(json, decrypt) {
-  var priv, pub, compressed, key, w;
+  var compressed, key, w;
+  var priv = json.priv;
+  var pub = json.pub;
+  var xprivkey = json.xprivkey;
+  var multisig = json.multisig;
 
-  assert.equal(json.v, 1);
+  assert.equal(json.v, 2);
   assert.equal(json.type, 'wallet');
 
   if (json.network)
@@ -639,11 +638,11 @@ Wallet.fromJSON = function fromJSON(json, decrypt) {
   if (json.encrypted && !decrypt)
     throw new Error('Cannot decrypt wallet');
 
-  if (json.encrypted)
-    json.priv = decrypt(json.priv);
+  if (priv) {
+    if (json.encrypted)
+      priv = decrypt(priv);
 
-  if (json.priv) {
-    key = bcoin.utils.fromBase58(json.priv);
+    key = bcoin.utils.fromBase58(priv);
     assert(utils.isEqual(key.slice(-4), utils.checksum(key.slice(0, -4))));
     assert.equal(key[0], network.prefixes.privkey);
 
@@ -657,20 +656,23 @@ Wallet.fromJSON = function fromJSON(json, decrypt) {
       compressed = false;
     }
   } else {
-    pub = bcoin.utils.fromBase58(json.pub);
+    pub = bcoin.utils.fromBase58(pub);
     compressed = pub[0] !== 0x04;
   }
 
-  if (json.multisig)
-    json.multisig.keys = json.multisig.keys.map(utils.fromBase58);
+  if (multisig) {
+    multisig = {
+      type: multisig.type,
+      keys: multisig.keys.map(utils.fromBase58),
+      m: multisig.m,
+      n: multisig.n
+    };
+  }
 
-  if (json.hd) {
-    json.hd.privateKey = priv;
-    if (json.encrypted && json.hd.seed) {
-      json.hd.seed.mnemonic = decrypt(json.hd.seed.mnemonic);
-      json.hd.seed.passphrase = decrypt(json.hd.seed.passphrase);
-    }
-    priv = bcoin.hd.priv(json.hd);
+  if (xprivkey) {
+    if (json.encrypted)
+      xprivkey = decrypt(xprivkey);
+    priv = bcoin.hd.priv(xprivkey);
   }
 
   w = new Wallet({
@@ -678,7 +680,7 @@ Wallet.fromJSON = function fromJSON(json, decrypt) {
     priv: priv,
     pub: pub,
     compressed: compressed,
-    multisig: json.multisig
+    multisig: multisig
   });
 
   w.tx.fromJSON(json.tx);