diff --git a/lib/bcoin.js b/lib/bcoin.js
index 18e83527..b3301b1c 100644
--- a/lib/bcoin.js
+++ b/lib/bcoin.js
@@ -27,6 +27,8 @@ bcoin.tx = require('./bcoin/tx');
 bcoin.txPool = require('./bcoin/tx-pool');
 bcoin.block = require('./bcoin/block');
 bcoin.chain = require('./bcoin/chain');
+bcoin.keypair = require('./bcoin/keypair');
+bcoin.address = require('./bcoin/address');
 bcoin.wallet = require('./bcoin/wallet');
 bcoin.peer = require('./bcoin/peer');
 bcoin.pool = require('./bcoin/pool');
diff --git a/lib/bcoin/address.js b/lib/bcoin/address.js
new file mode 100644
index 00000000..35d31771
--- /dev/null
+++ b/lib/bcoin/address.js
@@ -0,0 +1,431 @@
+/**
+ * address.js - address object for bcoin
+ * Copyright (c) 2014-2015, Fedor Indutny (MIT License)
+ * https://github.com/indutny/bcoin
+ */
+
+var bcoin = require('../bcoin');
+var hash = require('hash.js');
+var bn = require('bn.js');
+var inherits = require('inherits');
+var EventEmitter = require('events').EventEmitter;
+var utils = bcoin.utils;
+var assert = utils.assert;
+var constants = bcoin.protocol.constants;
+var network = bcoin.protocol.network;
+
+/**
+ * Address
+ */
+
+function Address(options) {
+  if (!(this instanceof Address))
+    return new Address(options);
+
+  EventEmitter.call(this);
+
+  if (!options)
+    options = {};
+
+  this.options = options;
+  this.storage = options.storage;
+  this.label = options.label || '';
+  this.change = !!options.change;
+
+  this.key = bcoin.keypair({
+    priv: options.priv,
+    pub: options.pub,
+    hd: options.hd,
+    key: options.key,
+    personalization: options.personalization,
+    entropy: options.entropy,
+    compressed: options.compressed
+  });
+
+  // Compatability
+  if (options.multisig) {
+    if (options.multisig.type)
+      options.type = options.multisig.type;
+    if (options.multisig.keys)
+      options.keys = options.multisig.keys;
+    if (options.multisig.m)
+      options.m = options.multisig.m;
+    if (options.multisig.n)
+      options.n = options.multisig.n;
+  }
+
+  this.type = options.type || 'pubkeyhash';
+  this.subtype = options.subtype;
+  this.keys = [];
+  this.m = options.m || 1;
+  this.n = options.n || 1;
+  this.redeem = null;
+
+  if (this.n > 1) {
+    if (this.type !== 'multisig')
+      this.type = 'scripthash';
+    if (this.type === 'scripthash')
+      this.subtype = 'multisig';
+  }
+
+  if (network.prefixes[this.type] == null)
+    throw new Error('Unknown prefix: ' + this.type);
+
+  this.nmax = this.type === 'scripthash'
+    ? (this.key.compressed ? 15 : 7)
+    : 3;
+
+  if (this.m < 1 || this.m > this.n)
+    throw new Error('m ranges between 1 and n');
+
+  if (this.n < 1 || this.n > this.nmax)
+    throw new Error('n ranges between 1 and ' + this.nmax);
+
+  this.addKey(this.getPublicKey());
+
+  (options.keys || []).forEach(function(key) {
+    this.addKey(key);
+  }, this);
+
+  if (options.redeem)
+    this.setRedeem(options.redeem);
+
+  this.prefix = 'bt/address/' + this.getKeyAddress() + '/';
+}
+
+inherits(Address, EventEmitter);
+
+Address.prototype.setRedeem = function setRedeem(redeem) {
+  var old = this.getScriptAddress();
+
+  if (!utils.isBytes(redeem))
+    redeem = bcoin.script.encode(redeem);
+
+  this.type = 'scripthash';
+  this.subtype = null;
+  this.redeem = redeem;
+  this.emit('scriptaddress', old, this.getScriptAddress());
+};
+
+Address.prototype.addKey = function addKey(key) {
+  var old = this.getScriptAddress();
+
+  key = utils.toBuffer(key);
+
+  var has = this.keys.some(function(k) {
+    return utils.isEqual(k, key);
+  });
+
+  if (has)
+    return;
+
+  this.keys.push(key);
+
+  this.keys = utils.sortKeys(this.keys);
+  this.emit('scriptaddress', old, this.getScriptAddress());
+};
+
+Address.prototype.removeKey = function removeKey(key) {
+  var old = this.getScriptAddress();
+
+  key = utils.toBuffer(key);
+
+  var index = this.keys.map(function(key, i) {
+    return utils.isEqual(key, pub) ? i : null;
+  }).filter(function(i) {
+    return i !== null;
+  })[0];
+
+  if (index == null)
+    return;
+
+  this.keys.splice(index, 1);
+
+  this.keys = utils.sortKeys(this.keys);
+  this.emit('scriptaddress', old, this.getScriptAddress());
+};
+
+Address.prototype.getPrivateKey = function getPrivateKey(enc) {
+  return this.key.getPrivate(enc);
+};
+
+Address.toSecret = function toSecret(priv, compressed) {
+  return bcoin.keypair.toSecret(priv, compressed);
+};
+
+Address.fromSecret = function fromSecret(priv) {
+  return bcoin.keypair.fromSecret(priv);
+};
+
+Address.prototype.getScript = function getScript() {
+  if (this.type !== 'scripthash')
+    return;
+
+  if (this.redeem)
+    return this.redeem.slice();
+
+  if (this.subtype === 'pubkey')
+    return bcoin.script.encode([this.getPublicKey(), 'checksig']);
+
+  if (this.subtype === 'pubkeyhash' || this.keys.length < this.n) {
+    return bcoin.script.encode([
+      'dup',
+      'hash160',
+      this.getKeyHash(),
+      'equalverify',
+      'checksig'
+    ]);
+  }
+
+  return bcoin.script.encode(
+    bcoin.script.createMultisig(this.keys, this.m, this.n)
+  );
+};
+
+Address.prototype.getScriptHash = function getScriptHash() {
+  if (this.type !== 'scripthash')
+    return;
+
+  return utils.ripesha(this.getScript());
+};
+
+Address.prototype.getScriptAddress = function getScriptAddress() {
+  if (this.type !== 'scripthash')
+    return;
+
+  return Address.hash2addr(this.getScriptHash(), this.type);
+};
+
+Address.prototype.getPublicKey = function getPublicKey(enc) {
+  return this.key.getPublic(enc);
+};
+
+Address.prototype.getKeyHash = function getKeyHash() {
+  return Address.key2hash(this.getPublicKey());
+};
+
+Address.prototype.getKeyAddress = function getKeyAddress() {
+  return Address.hash2addr(this.getKeyHash(), 'pubkeyhash');
+};
+
+Address.prototype.getHash = function getHash() {
+  if (this.type === 'scripthash')
+    return this.getScriptHash();
+  return this.getKeyHash();
+};
+
+Address.prototype.getAddress = function getAddress() {
+  if (this.type === 'scripthash')
+    return this.getScriptAddress();
+  return this.getKeyAddress();
+};
+
+Address.key2hash = function key2hash(key) {
+  key = utils.toBuffer(key);
+  return utils.ripesha(key);
+};
+
+Address.hash2addr = function hash2addr(hash, prefix) {
+  var addr;
+
+  hash = utils.toArray(hash, 'hex');
+
+  prefix = network.prefixes[prefix || 'pubkeyhash'];
+  hash = [ prefix ].concat(hash);
+
+  addr = hash.concat(utils.checksum(hash));
+
+  return utils.toBase58(addr);
+};
+
+Address.__defineGetter__('prefixes', function() {
+  if (Address._prefixes)
+    return Address._prefixes;
+
+  Address._prefixes = ['pubkeyhash', 'scripthash'].reduce(function(out, prefix) {
+    var ch = Address.hash2addr(Address.key2hash([]), prefix)[0];
+    out[ch] = prefix;
+    return out;
+  }, {});
+
+  return Address._prefixes;
+});
+
+Address.addr2hash = function addr2hash(addr, prefix) {
+  var chk;
+
+  if (prefix == null && typeof addr === 'string')
+    prefix = Address.prefixes[addr[0]];
+
+  if (!utils.isBuffer(addr))
+    addr = utils.fromBase58(addr);
+
+  prefix = network.prefixes[prefix || 'pubkeyhash'];
+
+  if (addr.length !== 25)
+    return [];
+
+  if (addr[0] !== prefix)
+    return [];
+
+  chk = utils.checksum(addr.slice(0, -4));
+
+  if (utils.readU32(chk, 0) !== utils.readU32(addr, 21))
+    return [];
+
+  return addr.slice(1, -4);
+};
+
+Address.validate = function validateAddress(addr, prefix) {
+  if (!addr || typeof addr !== 'string')
+    return false;
+
+  var p = Address.addr2hash(addr, prefix);
+
+  return p.length !== 0;
+};
+
+Address.validateAddress = Address.validate;
+
+Address.prototype.ownOutput = function ownOutput(tx, index) {
+  var scripthash = this.getScriptHash();
+  var hash = this.getKeyHash();
+  var key = this.getPublicKey();
+  var keys = this.keys;
+
+  var outputs = tx.outputs.filter(function(output, i) {
+    var s = output.script;
+
+    if (index != null && index !== i)
+      return false;
+
+    if (bcoin.script.isPubkey(s, key))
+      return true;
+
+    if (bcoin.script.isPubkeyhash(s, hash))
+      return true;
+
+    if (bcoin.script.isMultisig(s, keys))
+      return true;
+
+    if (scripthash) {
+      if (bcoin.script.isScripthash(s, scripthash))
+        return true;
+    }
+
+    return false;
+  }, this);
+
+  if (outputs.length === 0)
+    return false;
+
+  return outputs;
+};
+
+Address.prototype.ownInput = function ownInput(tx, index) {
+  var scripthash = this.getScriptHash();
+  var hash = this.getKeyHash();
+  var key = this.getPublicKey();
+  var redeem = this.getScript();
+  var keys = this.keys;
+
+  var inputs = tx.inputs.filter(function(input, i) {
+    var s;
+
+    if (!input.prevout.tx && this.tx._all[input.prevout.hash])
+      input.prevout.tx = this.tx._all[input.prevout.hash];
+
+    if (index != null && index !== i)
+      return false;
+
+    // if (bcoin.script.isPubkeyInput(input.script, key, tx, i))
+    //   return true;
+
+    if (bcoin.script.isPubkeyhashInput(input.script, key))
+      return true;
+
+    // if (bcoin.script.isMultisigInput(input.script, keys, tx, i))
+    //   return true;
+
+    if (redeem) {
+      if (bcoin.script.isScripthashInput(input.script, redeem))
+        return true;
+    }
+
+    if (!input.prevout.tx)
+      return false;
+
+    s = input.prevout.tx.getSubscript(input.prevout.index);
+
+    if (bcoin.script.isPubkey(s, key))
+      return true;
+
+    if (bcoin.script.isPubkeyhash(s, hash))
+      return true;
+
+    if (bcoin.script.isMultisig(s, keys))
+      return true;
+
+    if (scripthash) {
+      if (bcoin.script.isScripthash(s, scripthash))
+        return true;
+    }
+
+    return false;
+  }, this);
+
+  if (inputs.length === 0)
+    return false;
+
+  return inputs;
+};
+
+Address.prototype.toJSON = function toJSON(encrypt) {
+  return {
+    v: 1,
+    name: 'address',
+    network: network.type,
+    label: this.label,
+    change: this.change,
+    address: this.getKeyAddress(),
+    scriptaddress: this.getScriptAddress(),
+    key: this.key.toJSON(encrypt),
+    type: this.type,
+    subtype: this.subtype,
+    redeem: this.redeem ? utils.toHex(this.redeem) : null,
+    keys: this.keys.map(utils.toBase58),
+    m: this.m,
+    n: this.n
+  };
+};
+
+Address.fromJSON = function fromJSON(json, decrypt) {
+  var priv, pub, xprivkey, multisig, compressed, key, w;
+
+  assert.equal(json.v, 1);
+  assert.equal(json.name, 'address');
+
+  if (json.network)
+    assert.equal(json.network, network.type);
+
+  w = new Address({
+    label: json.label,
+    change: json.change,
+    key: bcoin.keypair.fromJSON(json.key, decrypt),
+    multisig: multisig,
+    type: json.type,
+    subtype: json.subtype,
+    redeem: json.redeem ? utils.toArray(json.redeem, 'hex') : null,
+    keys: json.keys.map(utils.fromBase58),
+    m: json.m,
+    n: json.n
+  });
+
+  return w;
+};
+
+/**
+ * Expose
+ */
+
+module.exports = Address;
diff --git a/lib/bcoin/hd.js b/lib/bcoin/hd.js
index b0e6a73d..72f4816b 100644
--- a/lib/bcoin/hd.js
+++ b/lib/bcoin/hd.js
@@ -126,9 +126,12 @@ function HDPrivateKey(options) {
   if (!options)
     options = { seed: bcoin.hd.seed() };
 
-  if (typeof options === 'string' && options.indexOf('xprv') === 0)
+  if (HDPrivateKey.isExtended(options))
     options = { xkey: options };
 
+  if (HDPublicKey.isExtended(options))
+    return new HDPublicKey(options);
+
   if (options.passphrase !== undefined
       || options.bits
       || options.entropy
@@ -157,8 +160,171 @@ function HDPrivateKey(options) {
   this.data = data;
 
   this._build(data);
+
+  if (new bn(data.parentFingerPrint).cmpn(0) === 0) {
+    this.isMaster = true;
+    this.master = this;
+  } else {
+    this.master = options.master;
+  }
+
+  this.purpose = options.purpose != null
+    ? options.purpose
+    : 44;
+
+  this.coinType = options.coinType != null
+    ? options.coinType
+    : (network.type === 'main' ? 0 : 1);
+
+  this.accountIndex = options.accountIndex != null
+    ? options.accountIndex
+    : 0;
+
+  this.isChange = options.isChange != null
+    ? options.isChange
+    : false;
+
+  // this.addressIndex = options.addressIndex != null
+  //   ? options.addressIndex
+  //   : 0;
+
+  this.isPrivate = true;
 }
 
+HDPrivateKey.prototype.scan = function scan(txs) {
+  var keys = [];
+
+  assert(this.isMaster);
+
+  // 0. get the root node
+  var root = master
+    .derive(44, true)
+    .derive(network.type === 'main' ? 0 : 1, true);
+
+  return (function scanner(accountIndex) {
+    var account, chain, addressIndex, address, addr, i;
+    var gap = 0;
+
+    // 1. derive the first account's node (index = 0)
+    account = root.derive(accountIndex, true);
+
+    // 2. derive the external chain node of this account
+    chain = account.derive(0);
+
+    // 3. scan addresses of the external chain;
+    // respect the gap limit described below
+    addressIndex = 0;
+main:
+    for (;;) {
+      address = chain.derive(addressIndex++);
+      addr = bcoin.address.hash2addr(
+        bcoin.address.key2hash(address.publicKey),
+        'pubkey');
+
+      for (i = 0; i < txs.length; i++) {
+        txs[i].fillPrevout(txs);
+        if (txs[i].testInputs(addr) || txs[i].testOutputs(addr)) {
+          keys.push(address);
+          gap = 0;
+        } else {
+          // 4. if no transactions are found on the
+          // external chain, stop discovery
+          if (++gap >= 20)
+            return keys;
+        }
+      }
+    }
+
+    // 5. if there are some transactions, increase
+    // the account index and go to step 1
+    return scanner(accountIndex + 1);
+  })(0);
+};
+
+HDPrivateKey.prototype.__defineGetter__('addressIndex', function() {
+  var index = this.childIndex;
+  assert(index < contants.hd.hardened);
+  return index;
+});
+
+HDPrivateKey.prototype._deriveBIP44 = function _deriveBIP44() {
+  var child;
+
+  assert(this.isMaster);
+
+  if (options.purpose == null)
+    options.purpose = 44;
+
+  if (options.coinType == null)
+    options.coinType = network.type === 'main' ? 0 : 1;
+
+  child = this
+    .derive(options.purpose, true)
+    .derive(options.coinType, true)
+    .derive(options.accountIndex, true)
+    .derive(options.isChange ? 1 : 0)
+    .derive(options.addressIndex);
+
+  child.purpose = options.purpose;
+  child.coinType = options.coinType;
+  child.accountIndex = options.accountIndex;
+  child.isChange = options.isChange;
+  child.addressIndex = options.addressIndex;
+
+  return child;
+};
+
+HDPrivateKey.prototype.deriveAccount = function deriveAccount(accountIndex) {
+  return this._deriveBIP44({
+    purpose: this.purpose,
+    coinType: this.coinType,
+    accountIndex: accountIndex != null ? accountIndex : this.accountIndex + 1,
+    isChange: false,
+    addressIndex: 0
+  });
+};
+
+HDPrivateKey.prototype.deriveChange = function deriveChange(addressIndex, accountIndex) {
+  return this._deriveBIP44({
+    purpose: this.purpose,
+    coinType: this.coinType,
+    accountIndex: accountIndex != null ? accountIndex : this.accountIndex,
+    isChange: true,
+    addressIndex: addressIndex != null ? addressIndex : this.addressIndex + 1
+  });
+};
+
+HDPrivateKey.prototype.deriveAddress = function deriveAddress(addressIndex, accountIndex) {
+  return this._deriveBIP44({
+    purpose: this.purpose,
+    coinType: this.coinType,
+    accountIndex: accountIndex != null ? accountIndex : this.accountIndex,
+    isChange: false,
+    addressIndex: addressIndex != null ? addressIndex : this.addressIndex + 1
+  });
+};
+
+HDPrivateKey.prototype.toPath = function toPath(data) {
+  assert(!this.isMaster);
+  return HDPrivateKey.getPath(
+    this.accountIndex, this.addressIndex, this.isChange);
+};
+
+HDPrivateKey.getPath = function toPath(accountIndex, addressIndex, isChange) {
+  return 'm/44\'/'
+    + (network.type === 'main' ? '0' : '1') + '\'' + '/'
+    + accountIndex + '\'/'
+    + (isChange ? '1' : '0') + '/'
+    + addressIndex;
+};
+
+HDPrivateKey.isExtended = function isExtended(data) {
+  if (typeof data !== 'string')
+    return false;
+
+  return data.indexOf('xprv') === 0 || data.indexOf('tprv') === 0;
+};
+
 HDPrivateKey.prototype._normalize = function _normalize(data, version) {
   data.version = version || network.prefixes.xprivkey;
   data.privateKey = data.privateKey || data.priv;
@@ -350,7 +516,8 @@ HDPrivateKey.prototype.derive = function derive(index, hardened) {
     childIndex: index,
     chainCode: chainCode,
     privateKey: privateKey,
-    checksum: null
+    checksum: null,
+    master: this.master
   });
 };
 
@@ -378,6 +545,19 @@ HDPrivateKey._getIndexes = function _getIndexes(path) {
       return null;
 
     index = +step;
+
+    if (i === 0) {
+      indexes.purpose = index;
+    } else if (i === 1) {
+      indexes.coinType = index;
+    } else if (i === 2) {
+      indexes.accountIndex = index;
+    } else if (i === 3) {
+      indexes.isChange = index === 1;
+    } else if (i === 4) {
+      indexes.addressIndex = index;
+    }
+
     if (hardened)
       index += constants.hd.hardened;
 
@@ -388,15 +568,16 @@ HDPrivateKey._getIndexes = function _getIndexes(path) {
 };
 
 HDPrivateKey.isValidPath = function isValidPath(path, hardened) {
+  var indexes;
+
   if (typeof path === 'string') {
-    var indexes = HDPrivateKey._getIndexes(path);
+    indexes = HDPrivateKey._getIndexes(path);
     return indexes !== null && indexes.every(HDPrivateKey.isValidPath);
   }
 
   if (typeof path === 'number') {
-    if (path < constants.hd.hardened && hardened) {
+    if (path < constants.hd.hardened && hardened)
       path += constants.hd.hardened;
-    }
     return path >= 0 && path < constants.hd.maxIndex;
   }
 
@@ -404,14 +585,24 @@ HDPrivateKey.isValidPath = function isValidPath(path, hardened) {
 };
 
 HDPrivateKey.prototype.deriveString = function deriveString(path) {
+  var indexes, child;
+
   if (!HDPrivateKey.isValidPath(path))
     throw new Error('invalid path');
 
-  var indexes = HDPrivateKey._getIndexes(path);
+  indexes = HDPrivateKey._getIndexes(path);
 
-  return indexes.reduce(function(prev, index) {
+  child = indexes.reduce(function(prev, index, i) {
     return prev.derive(index);
   }, this);
+
+  child.purpose = indexes.purpose;
+  child.coinType = indexes.coinType;
+  child.accountIndex = indexes.accountIndex;
+  child.isChange = indexes.isChange;
+  child.addressIndex = indexes.addressIndex;
+
+  return child;
 };
 
 /**
@@ -427,7 +618,7 @@ function HDPublicKey(options) {
   if (!options)
     throw new Error('No options for HDPublicKey');
 
-  if (typeof options === 'string' && options.indexOf('xpub') === 0)
+  if (HDPublicKey.isExtended(data))
     options = { xkey: options };
 
   data = options.xkey
@@ -439,8 +630,56 @@ function HDPublicKey(options) {
   this.data = data;
 
   this._build(data);
+
+  if (new bn(data.parentFingerPrint).cmpn(0) === 0) {
+    this.isMaster = true;
+    this.master = this;
+  } else {
+    this.master = options.master;
+  }
+
+  this.purpose = options.purpose != null
+    ? options.purpose
+    : 44;
+
+  this.coinType = options.coinType != null
+    ? options.coinType
+    : (network.type === 'main' ? 0 : 1);
+
+  this.accountIndex = options.accountIndex != null
+    ? options.accountIndex
+    : 0;
+
+  this.isChange = options.isChange != null
+    ? options.isChange
+    : false;
+
+  // this.addressIndex = options.addressIndex != null
+  //   ? options.addressIndex
+  //   : 0;
+
+  this.isPublic = true;
 }
 
+HDPublicKey.prototype.__defineGetter__('addressIndex', function() {
+  var index = this.childIndex;
+  assert(index < contants.hd.hardened);
+  return index;
+});
+
+HDPublicKey.prototype._deriveBIP44 = HDPrivateKey.prototype._deriveBIP44;
+HDPublicKey.prototype.deriveAccount = HDPrivateKey.prototype.deriveAccount;
+HDPublicKey.prototype.deriveChange = HDPrivateKey.prototype.deriveChange;
+HDPublicKey.prototype.deriveAddress = HDPrivateKey.prototype.deriveAddress;
+HDPublicKey.prototype.toPath = HDPrivateKey.prototype.toPath;
+
+HDPublicKey.isExtended = function isExtended(data) {
+  if (typeof data !== 'string')
+    return false;
+
+  return data.indexOf('xpub') === 0 || data.indexOf('tpub') === 0;
+};
+
 HDPublicKey.prototype._normalize = HDPrivateKey.prototype._normalize;
 
 HDPublicKey.prototype._unbuild = function _unbuild(xkey) {
@@ -546,7 +785,8 @@ HDPublicKey.prototype.derive = function derive(index, hardened) {
     childIndex: index,
     chainCode: chainCode,
     publicKey: publicKey,
-    checksum: null
+    checksum: null,
+    master: this.master
   });
 };
 
diff --git a/lib/bcoin/keypair.js b/lib/bcoin/keypair.js
new file mode 100644
index 00000000..ba81013d
--- /dev/null
+++ b/lib/bcoin/keypair.js
@@ -0,0 +1,270 @@
+/**
+ * keypair.js - keypair object for bcoin
+ * Copyright (c) 2014-2015, Fedor Indutny (MIT License)
+ * https://github.com/indutny/bcoin
+ */
+
+var bcoin = require('../bcoin');
+var hash = require('hash.js');
+var bn = require('bn.js');
+var inherits = require('inherits');
+var EventEmitter = require('events').EventEmitter;
+var utils = bcoin.utils;
+var assert = utils.assert;
+var constants = bcoin.protocol.constants;
+var network = bcoin.protocol.network;
+
+/**
+ * KeyPair
+ */
+
+function KeyPair(options) {
+  if (!(this instanceof KeyPair))
+    return new KeyPair(options);
+
+  if (!options)
+    options = {};
+
+  if (options instanceof KeyPair)
+    return options;
+
+  if (options.key instanceof KeyPair)
+    return options.key;
+
+  this.options = options;
+  this.key = options.key || null;
+  this.hd = options.hd || null;
+  this.compressed = options.compressed !== false;
+
+  if (options.priv instanceof bcoin.hd.priv) {
+    this.hd = options.priv;
+    this.key = options.priv.pair;
+  } else if (options.pub instanceof bcoin.hd.pub) {
+    this.hd = options.pub;
+    this.key = options.pub.pair;
+  } else if (options.hd) {
+    this.hd = typeof options.hd === 'object'
+      ? bcoin.hd.priv(options.hd)
+      : bcoin.hd.priv();
+    this.key = this.hd.pair;
+  } else if (options.key) {
+    if ((options.key instanceof bcoin.hd.priv)
+        || (options.key instanceof bcoin.hd.pub)) {
+      this.hd = options.key;
+      this.key = options.key.pair;
+    } else {
+      this.key = options.key;
+    }
+  } else if (options.priv || options.pub) {
+    this.key = bcoin.ecdsa.keyPair({
+      priv: options.priv,
+      pub: options.pub
+    });
+  } else {
+    this.key = bcoin.ecdsa.genKeyPair({
+      pers: options.personalization,
+      entropy: options.entropy
+        || (options.passphrase ? utils.sha256(options.passphrase) : null)
+    });
+  }
+}
+
+KeyPair.prototype.__defineGetter__('priv', function() {
+  return this.key.getPrivate();
+});
+
+KeyPair.prototype.__defineGetter__('pub', function() {
+  return this.key.getPublic();
+});
+
+KeyPair.prototype.getPrivate = function getPrivate(enc) {
+  var priv = this.key.getPrivate();
+
+  if (!priv)
+    return;
+
+  priv = priv.toArray();
+
+  if (enc === 'base58')
+    return KeyPair.toSecret(priv, this.compressed);
+
+  if (enc === 'hex')
+    return utils.toHex(priv);
+
+  return priv;
+};
+
+KeyPair.prototype.getPublic = function getPublic(enc) {
+  var pub = this.key.getPublic(this.compressed, 'array');
+
+  if (enc === 'base58')
+    return utils.toBase58(pub);
+
+  if (enc === 'hex')
+    return utils.toHex(pub);
+
+  return pub;
+};
+
+KeyPair.prototype.toSecret = function toSecret() {
+  return KeyPair.toSecret(this.getPrivate(), this.compressed);
+};
+
+KeyPair.toSecret = function toSecret(priv, compressed) {
+  var arr, chk;
+
+  // We'll be using ncompressed public key as an address
+  arr = [network.prefixes.privkey];
+
+  // 0-pad key
+  while (arr.length + priv.length < 33)
+    arr.push(0);
+
+  arr = arr.concat(priv);
+
+  if (compressed)
+    arr.push(1);
+
+  chk = utils.checksum(arr);
+
+  return utils.toBase58(arr.concat(chk));
+};
+
+KeyPair.fromSecret = function fromSecret(priv) {
+  var key, compressed;
+
+  key = utils.fromBase58(priv);
+  assert(utils.isEqual(key.slice(-4), utils.checksum(key.slice(0, -4))));
+  assert.equal(key[0], network.prefixes.privkey);
+
+  key = key.slice(0, -4);
+  if (key.length === 34) {
+    assert.equal(key[33], 1);
+    priv = key.slice(1, -1);
+    compressed = true;
+  } else {
+    priv = key.slice(1);
+    compressed = false;
+  }
+
+  return new KeyPair({
+    priv: priv,
+    compressed: compressed
+  });
+};
+
+KeyPair.prototype.toJSON = function toJSON(encrypt) {
+  var json = {
+    v: 1,
+    name: 'keypair',
+    encrypted: encrypt ? true : false
+  };
+
+  if (this.hd) {
+    if (this.hd.xprivkey) {
+      if (this.hd.seed) {
+        json.mnemonic = encrypt
+          ? encrypt(this.hd.seed.mnemonic)
+          : this.hd.seed.mnemonic;
+        json.passphrase = encrypt
+          ? encrypt(this.hd.seed.passphrase)
+          : this.hd.seed.passphrase;
+        return json;
+      }
+      json.xpriv = encrypt
+        ? encrypt(this.hd.xprivkey)
+        : this.hd.xprivkey;
+      return json;
+    }
+
+    json.xpub = this.hd.xpubkey;
+
+    return json;
+  }
+
+  if (this.key.priv) {
+    json.priv = encrypt
+      ? encrypt(this.getPrivate('base58'))
+      : this.getPrivate('base58');
+    return json;
+  }
+
+  json.pub = this.getPublic('hex');
+  return json;
+};
+
+KeyPair.fromJSON = function fromJSON(json, decrypt) {
+  var key, priv, pub, compressed, xprivkey;
+  var path = {};
+
+  assert.equal(json.v, 1);
+  assert.equal(json.name, 'keypair');
+
+  if (json.encrypted && !decrypt)
+    throw new Error('Cannot decrypt address');
+
+  if (json.mnemonic) {
+    return new KeyPair({
+      key: bcoin.hd.priv({
+        seed: bcoin.hd.seed({
+          mnemonic: json.encrypted
+            ? decrypt(json.mnemonic)
+            : json.mnemonic,
+          passphrase: json.encrypted
+            ? decrypt(json.passphrase)
+            : json.passphrase
+        })
+      })
+    });
+  }
+
+  if (json.xpriv) {
+    xprivkey = json.xpriv;
+    if (json.encrypted)
+      xprivkey = decrypt(xprivkey);
+    return new KeyPair({
+      key: bcoin.hd.priv({
+        xkey: xprivkey
+      })
+    });
+  }
+
+  if (json.xpub) {
+    return new KeyPair({
+      key: bcoin.hd.pub({
+        xkey: json.xpub
+      })
+    });
+  }
+
+  if (json.priv) {
+    priv = json.priv;
+    if (json.encrypted)
+      priv = decrypt(priv);
+
+    key = KeyPair.fromSecret(json.priv);
+    priv = key.priv;
+    compressed = key.compressed;
+    return new KeyPair({
+      priv: priv,
+      compressed: compressed
+    });
+  }
+
+  if (json.pub) {
+    pub = bcoin.utils.toArray(json.pub, 'hex');
+    compressed = pub[0] !== 0x04;
+    return new KeyPair({
+      pub: pub,
+      compressed: compressed
+    });
+  }
+
+  assert(false);
+};
+
+/**
+ * Expose
+ */
+
+module.exports = KeyPair;
diff --git a/lib/bcoin/pool.js b/lib/bcoin/pool.js
index a1aaeced..6b02d561 100644
--- a/lib/bcoin/pool.js
+++ b/lib/bcoin/pool.js
@@ -921,6 +921,7 @@ Pool.prototype._removePeer = function _removePeer(peer) {
 };
 
 Pool.prototype.watch = function watch(id) {
+  var self = this;
   var hid, i;
 
   if (id instanceof bcoin.wallet) {
@@ -941,14 +942,25 @@ Pool.prototype.watch = function watch(id) {
     this.bloom.add(id, 'hex');
   }
 
-  if (this.peers.load)
-    this.peers.load.updateWatch();
+  // Send it to peers
+  if (this._pendingWatch)
+    return;
 
-  for (i = 0; i < this.peers.block.length; i++)
-    this.peers.block[i].updateWatch();
+  this._pendingWatch = true;
+
+  utils.nextTick(function() {
+    self._pendingWatch = false;
+
+    if (self.peers.load)
+      self.peers.load.updateWatch();
+
+    for (i = 0; i < self.peers.block.length; i++)
+      self.peers.block[i].updateWatch();
+  });
 };
 
 Pool.prototype.unwatch = function unwatch(id) {
+  var self = this;
   var i;
 
   id = utils.toHex(id);
@@ -968,11 +980,20 @@ Pool.prototype.unwatch = function unwatch(id) {
   }, this);
 
   // Resend it to peers
-  if (this.peers.load)
-    this.peers.load.updateWatch();
+  if (this._pendingWatch)
+    return;
 
-  for (i = 0; i < this.peers.block.length; i++)
-    this.peers.block[i].updateWatch();
+  this._pendingWatch = true;
+
+  utils.nextTick(function() {
+    self._pendingWatch = false;
+
+    if (self.peers.load)
+      self.peers.load.updateWatch();
+
+    for (i = 0; i < self.peers.block.length; i++)
+      self.peers.block[i].updateWatch();
+  });
 };
 
 // See "Filter matching algorithm":
@@ -1084,32 +1105,58 @@ Pool.prototype.removeWallet = function removeWallet(w) {
   this.unwatchWallet(w);
 };
 
-Pool.prototype.watchWallet = function watchWallet(w) {
-  if (w.type === 'scripthash') {
+Pool.prototype.watchAddress = function watchAddress(address) {
+  if (address.type === 'scripthash') {
     // For the redeem script hash in outputs:
-    this.watch(w.getScriptHash());
+    this.watch(address.getScriptHash());
     // For the redeem script in inputs:
-    this.watch(w.getScript());
+    this.watch(address.getScript());
   }
 
   // For the pubkey hash in outputs:
-  this.watch(w.getKeyHash());
+  this.watch(address.getKeyHash());
   // For the pubkey in inputs:
-  this.watch(w.getPublicKey());
+  this.watch(address.getPublicKey());
 };
 
-Pool.prototype.unwatchWallet = function unwatchWallet(w) {
-  if (w.type === 'scripthash') {
+Pool.prototype.unwatchAddress = function unwatchAddress(address) {
+  if (address.type === 'scripthash') {
     // For the redeem script hash in p2sh outputs:
-    this.unwatch(w.getScriptHash());
+    this.unwatch(address.getScriptHash());
     // For the redeem script in p2sh inputs:
-    this.unwatch(w.getScript());
+    this.unwatch(address.getScript());
   }
 
   // For the pubkey hash in p2pk/multisig outputs:
-  this.unwatch(w.getKeyHash());
+  this.unwatch(address.getKeyHash());
   // For the pubkey in p2pkh inputs:
-  this.unwatch(w.getPublicKey());
+  this.unwatch(address.getPublicKey());
+};
+
+Pool.prototype.watchWallet = function watchWallet(w) {
+  var self = this;
+
+  w.addresses.forEach(function(address) {
+    this.watchAddress(address);
+  }, this);
+
+  w.on('add address', w._poolOnAdd = function(address) {
+    self.watchAddress(address);
+  });
+
+  w.on('remove address', w._poolOnRemove = function(address) {
+    self.unwatchAddress(address);
+  });
+};
+
+Pool.prototype.unwatchWallet = function unwatchWallet(w) {
+  w.addresses.forEach(function(address) {
+    this.unwatchAddress(address);
+  }, this);
+  w.removeListener('add address', w._poolOnAdd);
+  w.removeListener('remove address', w._poolOnRemove);
+  delete w._poolOnAdd;
+  delete w._poolOnRemove;
 };
 
 Pool.prototype.searchWallet = function(w) {
diff --git a/lib/bcoin/tx.js b/lib/bcoin/tx.js
index 83f3aa63..956052e5 100644
--- a/lib/bcoin/tx.js
+++ b/lib/bcoin/tx.js
@@ -197,19 +197,20 @@ TX.prototype.scriptInput = function scriptInput(index, pub, redeem) {
   input = this.inputs[index];
   assert(input);
 
+  // Already has a script template (at least)
+  // if (input.script.length)
+  //   return;
+
   // We should have previous outputs by now.
   assert(input.prevout.tx);
 
-  // Already has a script template (at least)
-  if (input.script.length)
-    return;
-
   // Get the previous output's subscript
   s = input.prevout.tx.getSubscript(input.prevout.index);
 
   // P2SH
   if (bcoin.script.isScripthash(s)) {
-    assert(redeem);
+    if (!redeem)
+      return false;
     s = bcoin.script.getSubscript(bcoin.script.decode(redeem));
   } else {
     redeem = null;
@@ -217,12 +218,34 @@ TX.prototype.scriptInput = function scriptInput(index, pub, redeem) {
 
   if (bcoin.script.isPubkey(s)) {
     // P2PK
+    if (!utils.isEqual(s[0], pub))
+      return false;
+    // Already has a script template (at least)
+    if (input.script.length)
+      return true;
     input.script = [[]];
   } else if (bcoin.script.isPubkeyhash(s)) {
     // P2PKH
+    if (!utils.isEqual(s[2], bcoin.wallet.key2hash(pub)))
+      return false;
+    // Already has a script template (at least)
+    if (input.script.length)
+      return true;
     input.script = [[], pub];
   } else if (bcoin.script.isMultisig(s)) {
     // Multisig
+    for (i = 0; i < s.length; i++) {
+      if (utils.isEqual(s[i], pub))
+        break;
+    }
+
+    if (i === s.length)
+      return false;
+
+    // Already has a script template (at least)
+    if (input.script.length)
+      return true;
+
     // Technically we should create m signature slots,
     // but we create n signature slots so we can order
     // the signatures properly.
@@ -235,6 +258,18 @@ TX.prototype.scriptInput = function scriptInput(index, pub, redeem) {
     for (i = 0; i < n; i++)
       input.script[i + 1] = [];
   } else {
+    for (i = 0; i < s.length; i++) {
+      if (utils.isEqual(s[i], pub))
+        break;
+    }
+
+    if (i === s.length)
+      return false;
+
+    // Already has a script template (at least)
+    if (input.script.length)
+      return true;
+
     // Likely a non-standard scripthash multisig
     // input. Determine n value by counting keys.
     // Also, only allow nonstandard types for
@@ -256,6 +291,8 @@ TX.prototype.scriptInput = function scriptInput(index, pub, redeem) {
     // now that the redeem script is available.
     this._recalculateFee();
   }
+
+  return true;
 };
 
 TX.prototype.createSignature = function createSignature(index, key, type) {
@@ -501,10 +538,12 @@ TX.prototype.scriptSig = function scriptSig(index, key, pub, redeem, type) {
   assert(input);
 
   // Build script for input
-  this.scriptInput(index, pub, redeem);
+  if (!this.scriptInput(index, pub, redeem))
+    return false;
 
   // Sign input
-  this.signInput(index, key, type);
+  if (!this.signInput(index, key, type))
+    return false;
 
   return input.script;
 };
@@ -1131,6 +1170,111 @@ TX.prototype.getFunds = function getFunds(side) {
 // Legacy
 TX.prototype.funds = TX.prototype.getFunds;
 
+TX.prototype.testInputs = function testInputs(addressTable, index, collect) {
+  var inputs = [];
+  var i, input, prev, data, j;
+
+  if (typeof addressTable === 'string')
+    addressTable = [addressTable];
+
+  if (Array.isArray(addressTable)) {
+    addressTable = addressTable.reduce(function(address) {
+      out[address] = true;
+      return out;
+    }, {});
+  }
+
+  for (i = 0; i < this.inputs.length; i++) {
+    if (index != null && i !== index)
+      continue;
+
+    input = this.inputs[i];
+
+    if (input.prevout.tx)
+      prev = input.prevout.tx.outputs[input.prevout.index].script;
+    else
+      prev = null;
+
+    data = bcoin.script.getInputData(input.script, prev);
+
+    if (data.addresses) {
+      for (j = 0; j < data.addresses.length; j++) {
+        if (addressTable[data.addresses[j]] != null) {
+          if (!collect)
+            return true;
+          inputs.push(input);
+        }
+      }
+    }
+
+    if (data.scriptaddress) {
+      if (addressTable[data.scriptaddress] != null) {
+        if (!collect)
+          return true;
+        inputs.push(input);
+      }
+    }
+  }
+
+  if (!collect)
+    return false;
+
+  if (inputs.length === 0)
+    return false;
+
+  return inputs;
+};
+
+TX.prototype.testOutputs = function testOutputs(addressTable, index, collect) {
+  var outputs = [];
+  var i, output, data, j;
+
+  if (typeof addressTable === 'string')
+    addressTable = [addressTable];
+
+  if (Array.isArray(addressTable)) {
+    addressTable = addressTable.reduce(function(address) {
+      out[address] = true;
+      return out;
+    }, {});
+  }
+
+  for (i = 0; i < this.outputs.length; i++) {
+    if (index != null && i !== index)
+      continue;
+
+    output = this.outputs[i];
+
+    data = bcoin.script.getOutputData(output.script);
+
+    if (data.addresses) {
+      for (j = 0; j < data.addresses.length; j++) {
+        if (addressTable[data.addresses[j]] != null) {
+          if (!collect)
+            return true;
+          outputs.push(output);
+        }
+      }
+    }
+
+    if (data.scriptaddress) {
+      if (addressTable[data.scriptaddress] != null) {
+        if (!collect)
+          return true;
+        outputs.push(output);
+      }
+    }
+  }
+
+  if (!collect)
+    return false;
+
+  if (outputs.length === 0)
+    return false;
+
+  return outputs;
+};
+
 TX.prototype.avoidFeeSnipping = function avoidFeeSnipping() {
   if (!this.chain)
     return;
diff --git a/lib/bcoin/wallet.js b/lib/bcoin/wallet.js
index 6f0513bf..5b565994 100644
--- a/lib/bcoin/wallet.js
+++ b/lib/bcoin/wallet.js
@@ -18,115 +18,36 @@ var network = bcoin.protocol.network;
  * Wallet
  */
 
-function Wallet(options, passphrase) {
+function Wallet(options) {
   if (!(this instanceof Wallet))
-    return new Wallet(options, passphrase);
+    return new Wallet(options);
 
   EventEmitter.call(this);
 
-  if (typeof options === 'string' && typeof passphrase === 'string') {
-    options = {
-      scope: options,
-      passphrase: passphrase
-    };
-  }
-
   if (!options)
     options = {};
 
   this.options = options;
-  this.compressed = options.compressed !== false;
+  this.addresses = [];
+  this.master = null;
+  this._addressTable = {};
+
+  this.accountIndex = options.accountIndex || 0;
+  this.addressIndex = options.addressIndex || 0;
+  this.changeIndex = options.changeIndex || 0;
+
+  if (options.addresses) {
+    options.addresses.forEach(function(address) {
+      this.addAddress(address);
+    }, this);
+  } else {
+    this.addAddress(options);
+  }
+
   this.storage = options.storage;
   this.label = options.label || '';
-  this.key = null;
   this.loaded = false;
   this.lastTs = 0;
-  this.changeAddress = options.changeAddress || null;
-  this.redeem = options.redeem || options.script;
-
-  if (options.priv instanceof bcoin.hd.priv) {
-    this.hd = options.priv;
-    this.key = this.hd;
-  } else if (options.pub instanceof bcoin.hd.pub) {
-    this.hd = options.pub;
-    this.key = this.hd;
-  } else if (options.hd) {
-    this.hd = typeof options.hd === 'object'
-      ? bcoin.hd.priv(options.hd)
-      : bcoin.hd.priv();
-    this.key = this.hd;
-  } else if (options.key) {
-    if ((options.key instanceof bcoin.hd.priv)
-        || (options.key instanceof bcoin.hd.pub)) {
-      this.hd = options.key;
-      this.key = options.key;
-    } else {
-      this.key = options.key;
-    }
-  } else if (options.passphrase) {
-    this.key = bcoin.ecdsa.genKeyPair({
-      pers: options.scope,
-      entropy: hash.sha256().update(options.passphrase).digest()
-    });
-  } else if (options.priv || options.pub) {
-    this.key = bcoin.ecdsa.keyPair({
-      priv: options.priv,
-      pub: options.pub
-    });
-  } else {
-    this.key = bcoin.ecdsa.genKeyPair();
-  }
-
-  // Compatability
-  if (options.multisig) {
-    if (options.multisig.type)
-      options.type = options.multisig.type;
-    if (options.multisig.keys)
-      options.keys = options.multisig.keys;
-    if (options.multisig.m)
-      options.m = options.multisig.m;
-    if (options.multisig.n)
-      options.n = options.multisig.n;
-  }
-
-  this.type = options.type || 'pubkeyhash';
-  this.subtype = options.subtype;
-  this.keys = [];
-  this.m = options.m || 1;
-  this.n = options.n || 1;
-
-  if (this.n > 1) {
-    if (this.type !== 'multisig')
-      this.type = 'scripthash';
-    if (this.type === 'scripthash')
-      this.subtype = 'multisig';
-  }
-
-  if (network.prefixes[this.type] == null)
-    throw new Error('Unknown prefix: ' + this.type);
-
-  this.nmax = this.type === 'scripthash'
-    ? (this.compressed ? 15 : 7)
-    : 3;
-
-  if (this.m < 1 || this.m > this.n)
-    throw new Error('m ranges between 1 and n');
-
-  if (this.n < 1 || this.n > this.nmax)
-    throw new Error('n ranges between 1 and ' + this.nmax);
-
-  this.addKey(this.getPublicKey());
-
-  (options.keys || []).forEach(function(key) {
-    this.addKey(key);
-  }, this);
-
-  if (this.redeem) {
-    if (!utils.isBytes(this.redeem))
-      this.redeem = bcoin.script.encode(this.redeem);
-    this.type = 'scripthash';
-    this.subtype = null;
-  }
 
   this.prefix = 'bt/wallet/' + this.getKeyAddress() + '/';
 
@@ -170,342 +91,205 @@ Wallet.prototype._init = function init() {
   });
 };
 
-Wallet.prototype.addKey = function addKey(key) {
-  key = utils.toBuffer(key);
+Wallet.prototype.__defineGetter__('address', function() {
+  return this.addresses[0];
+});
 
-  var has = this.keys.some(function(k) {
-    return utils.isEqual(k, key);
-  });
+Wallet.prototype._getAddressTable = function() {
+  var addresses = {};
+  var i, address;
 
-  if (has)
+  for (i = 0; i < this.addresses.length; i++) {
+    address = this.addresses[i];
+    if (address.type === 'scripthash')
+      addresses[address.getScriptAddress()] = i;
+    addresses[address.getKeyAddress()] = i;
+  }
+
+  return addresses;
+};
+
+// Faster than indexOf if we have tons of addresses
+Wallet.prototype._addressIndex = function _addressIndex(address) {
+  var addr;
+
+  if (!(address instanceof bcoin.address))
+    address = bcoin.address(address);
+
+  if (address.type === 'scripthash') {
+    addr = address.getScriptAddress();
+    if (this._addressTable[addr] != null)
+      return this._addressTable[addr];
+  }
+
+  addr = address.getKeyAddress();
+  if (this._addressTable[addr] != null)
+    return this._addressTable[addr];
+
+  return -1;
+};
+
+Wallet.prototype.createChangeAddress = function createChangeAddress(address) {
+  if (!options)
+    options = {};
+
+  if (this.master) {
+    options.change = true;
+    options.priv = this.master.deriveAddress(this.addressIndex++, this.accountIndex);
+  }
+
+  return this.addAddress({ change: true });
+};
+
+Wallet.prototype.createNewAddress = function createNewAddress(address, options) {
+  if (!options)
+    options = {};
+
+  if (this.master)
+    options.priv = this.master.deriveAddress(this.addressIndex++, this.accountIndex);
+
+  return this.addAddress(options);
+};
+
+Wallet.prototype.hasAddress = function hasAddress(address) {
+  return this._addressIndex(address) != -1;
+};
+
+Wallet.prototype.findAddress = function findAddress(address) {
+  var i = this._addressIndex(address);
+
+  if (i === -1)
     return;
 
-  this.keys.push(key);
+  return this.addresses[i];
+};
 
-  this.keys = utils.sortKeys(this.keys);
+Wallet.prototype.addAddress = function addAddress(address) {
+  var self = this;
+  var index;
+
+  if (!(address instanceof bcoin.address))
+    address = bcoin.address(address);
+
+  if (this._addressIndex(address) !== -1)
+    return;
+
+  if (address._wallet)
+    address._wallet.removeAddress(address);
+
+  address._wallet = this;
+
+  index = this.addresses.push(address) - 1;
+
+  if (address.hd && address.hd.isMaster && adress.hd.isPrivate) {
+    assert(!this.master);
+    this.master = address;
+  }
+
+  address.on('scriptaddress', address._onUpdate = function(old, cur) {
+    self._addressTable[cur] = self._addressTable[old];
+    delete self._addressTable[old];
+  });
+
+  if (address.type === 'scripthash')
+    this._addressTable[address.getScriptAddress()] = index;
+
+  this._addressTable[address.getKeyAddress()] = index;
+
+  this.emit('add address', address);
+
+  return address;
+};
+
+Wallet.prototype.removeAddress = function removeAddress(address) {
+  var i;
+
+  assert(address instanceof bcoin.address);
+
+  i = this._addressIndex(address);
+
+  if (i === -1)
+    return;
+
+  assert(address._wallet === this);
+  assert(address._onUpdate);
+
+  this.addresses.splice(i, 1);
+
+  address.removeListener('scriptaddress', address._onUpdate);
+
+  this._addressTable = this._getAddressTable();
+
+  delete address._onUpdate;
+  delete address._wallet;
+
+  this.emit('remove address', address);
+
+  return address;
+};
+
+Wallet.prototype.addKey = function addKey(key, i) {
+  return this.address.addKey(key);
 };
 
 Wallet.prototype.removeKey = function removeKey(key) {
-  key = utils.toBuffer(key);
-
-  var index = this.keys.map(function(key, i) {
-    return utils.isEqual(key, pub) ? i : null;
-  }).filter(function(i) {
-    return i !== null;
-  })[0];
-
-  if (index == null)
-    return;
-
-  this.keys.splice(index, 1);
-
-  this.keys = utils.sortKeys(this.keys);
+  return this.address.removeKey(key);
 };
 
 Wallet.prototype.derive = function derive() {
-  var options = this.options;
-
-  if (!this.hd)
-    throw new Error('Wallet is not HD');
-
-  options.priv = this.hd.derive.apply(this.hd, arguments);
-
-  return new Wallet(options);
+  this.addAddress(this.address.derive.apply(this.address, arguments));
 };
 
 Wallet.prototype.getPrivateKey = function getPrivateKey(enc) {
-  var priv = this.key.getPrivate();
-  var arr, chk;
-
-  if (!priv)
-    return;
-
-  priv = priv.toArray();
-
-  if (!enc)
-    return priv;
-
-  if (enc === 'base58')
-    return Wallet.toSecret(priv, this.compressed);
-  else if (enc === 'hex')
-    return utils.toHex(priv);
-  else
-    return priv;
-};
-
-Wallet.toSecret = function toSecret(priv, compressed) {
-  var arr, chk;
-
-  // We'll be using ncompressed public key as an address
-  arr = [network.prefixes.privkey];
-
-  // 0-pad key
-  while (arr.length + priv.length < 33)
-    arr.push(0);
-
-  arr = arr.concat(priv);
-
-  if (compressed)
-    arr.push(1);
-
-  chk = utils.checksum(arr);
-
-  return utils.toBase58(arr.concat(chk));
-};
-
-Wallet.fromSecret = function fromSecret(priv) {
-  var key, compressed;
-
-  key = bcoin.utils.fromBase58(priv);
-  assert(utils.isEqual(key.slice(-4), utils.checksum(key.slice(0, -4))));
-  assert.equal(key[0], network.prefixes.privkey);
-
-  key = key.slice(0, -4);
-  if (key.length === 34) {
-    assert.equal(key[33], 1);
-    priv = key.slice(1, -1);
-    compressed = true;
-  } else {
-    priv = key.slice(1);
-    compressed = false;
-  }
-
-  return {
-    priv: priv,
-    compressed: compressed
-  };
+  return this.address.getPrivateKey(enc);
 };
 
 Wallet.prototype.getScript = function getScript() {
-  if (this.type !== 'scripthash')
-    return;
-
-  if (this.redeem)
-    return this.redeem.slice();
-
-  if (this.subtype === 'pubkey')
-    return bcoin.script.encode([this.getPublicKey(), 'checksig']);
-
-  if (this.subtype === 'pubkeyhash') {
-    return bcoin.script.encode([
-      'dup',
-      'hash160',
-      this.getKeyHash(),
-      'equalverify',
-      'checksig'
-    ]);
-  }
-
-  return bcoin.script.encode(
-    bcoin.script.createMultisig(this.keys, this.m, this.n)
-  );
+  return this.address.getScript();
 };
 
 Wallet.prototype.getScriptHash = function getScriptHash() {
-  if (this.type !== 'scripthash')
-    return;
-
-  return utils.ripesha(this.getScript());
+  return this.address.getScriptHash();
 };
 
 Wallet.prototype.getScriptAddress = function getScriptAddress() {
-  if (this.type !== 'scripthash')
-    return;
-
-  return Wallet.hash2addr(this.getScriptHash(), this.type);
+  return this.address.getScriptAddress();
 };
 
 Wallet.prototype.getPublicKey = function getPublicKey(enc) {
-  var pub = this.key.getPublic(this.compressed, 'array');
-
-  if (enc === 'base58')
-    return utils.toBase58(pub);
-  else if (enc === 'hex')
-    return utils.toHex(pub);
-  else
-    return pub;
+  return this.address.getPublicKey(enc);
 };
 
 Wallet.prototype.getKeyHash = function getKeyHash() {
-  return Wallet.key2hash(this.getPublicKey());
+  return this.address.getKeyHash();
 };
 
 Wallet.prototype.getKeyAddress = function getKeyAddress() {
-  return Wallet.hash2addr(this.getKeyHash(), 'pubkeyhash');
+  return this.address.getKeyAddress();
 };
 
 Wallet.prototype.getHash = function getHash() {
-  if (this.type === 'scripthash')
-    return this.getScriptHash();
-  return this.getKeyHash();
+  return this.address.getHash();
 };
 
 Wallet.prototype.getAddress = function getAddress() {
-  if (this.type === 'scripthash')
-    return this.getScriptAddress();
-  return this.getKeyAddress();
-};
-
-Wallet.key2hash = function key2hash(key) {
-  key = utils.toBuffer(key);
-  return utils.ripesha(key);
-};
-
-Wallet.hash2addr = function hash2addr(hash, prefix) {
-  var addr;
-
-  hash = utils.toArray(hash, 'hex');
-
-  prefix = network.prefixes[prefix || 'pubkeyhash'];
-  hash = [ prefix ].concat(hash);
-
-  addr = hash.concat(utils.checksum(hash));
-
-  return utils.toBase58(addr);
-};
-
-Wallet.__defineGetter__('prefixes', function() {
-  if (Wallet._prefixes) return Wallet._prefixes;
-  Wallet._prefixes = ['pubkeyhash', 'scripthash'].reduce(function(out, prefix) {
-    var ch = Wallet.hash2addr(Wallet.key2hash([]), prefix)[0];
-    out[ch] = prefix;
-    return out;
-  }, {});
-  return Wallet._prefixes;
-});
-
-Wallet.addr2hash = function addr2hash(addr, prefix) {
-  var chk;
-
-  if (prefix == null && typeof addr === 'string')
-    prefix = Wallet.prefixes[addr[0]];
-
-  if (!utils.isBuffer(addr))
-    addr = utils.fromBase58(addr);
-
-  prefix = network.prefixes[prefix || 'pubkeyhash'];
-
-  if (addr.length !== 25)
-    return [];
-
-  if (addr[0] !== prefix)
-    return [];
-
-  chk = utils.checksum(addr.slice(0, -4));
-
-  if (utils.readU32(chk, 0) !== utils.readU32(addr, 21))
-    return [];
-
-  return addr.slice(1, -4);
-};
-
-Wallet.validateAddress = function validateAddress(addr, prefix) {
-  if (!addr)
-    return false;
-
-  var p = Wallet.addr2hash(addr, prefix);
-
-  return p.length !== 0;
-};
-
-Wallet.prototype.ownOutput = function ownOutput(tx, index) {
-  var scripthash = this.getScriptHash();
-  var hash = this.getKeyHash();
-  var key = this.getPublicKey();
-  var keys = this.keys;
-
-  var outputs = tx.outputs.filter(function(output, i) {
-    var s = output.script;
-
-    if (index != null && index !== i)
-      return false;
-
-    if (bcoin.script.isPubkey(s, key))
-      return true;
-
-    if (bcoin.script.isPubkeyhash(s, hash))
-      return true;
-
-    if (bcoin.script.isMultisig(s, keys))
-      return true;
-
-    if (scripthash) {
-      if (bcoin.script.isScripthash(s, scripthash))
-        return true;
-    }
-
-    return false;
-  }, this);
-
-  if (outputs.length === 0)
-    return false;
-
-  return outputs;
+  return this.address.getAddress();
 };
 
 Wallet.prototype.ownInput = function ownInput(tx, index) {
-  var scripthash = this.getScriptHash();
-  var hash = this.getKeyHash();
-  var key = this.getPublicKey();
-  var redeem = this.getScript();
-  var keys = this.keys;
+  this.fillPrevout(tx);
+  return tx.testInputs(this._addressTable, index, true);
+};
 
-  var inputs = tx.inputs.filter(function(input, i) {
-    var s;
-
-    if (!input.prevout.tx && this.tx._all[input.prevout.hash])
-      input.prevout.tx = this.tx._all[input.prevout.hash];
-
-    if (index != null && index !== i)
-      return false;
-
-    // if (bcoin.script.isPubkeyInput(input.script, key, tx, i))
-    //   return true;
-
-    if (bcoin.script.isPubkeyhashInput(input.script, key))
-      return true;
-
-    // if (bcoin.script.isMultisigInput(input.script, keys, tx, i))
-    //   return true;
-
-    if (redeem) {
-      if (bcoin.script.isScripthashInput(input.script, redeem))
-        return true;
-    }
-
-    if (!input.prevout.tx)
-      return false;
-
-    s = input.prevout.tx.getSubscript(input.prevout.index);
-
-    if (bcoin.script.isPubkey(s, key))
-      return true;
-
-    if (bcoin.script.isPubkeyhash(s, hash))
-      return true;
-
-    if (bcoin.script.isMultisig(s, keys))
-      return true;
-
-    if (scripthash) {
-      if (bcoin.script.isScripthash(s, scripthash))
-        return true;
-    }
-
-    return false;
-  }, this);
-
-  if (inputs.length === 0)
-    return false;
-
-  return inputs;
+Wallet.prototype.ownOutput = function ownOutput(tx, index) {
+  return tx.testOutputs(this._addressTable, index, true);
 };
 
 Wallet.prototype.fill = function fill(tx, address, fee) {
   var result;
 
   if (!address)
-    address = this.changeAddress || this.getAddress();
+    address = this.createChangeAddress();
 
   result = tx.fill(this.getUnspent(), address, fee);
 
@@ -527,65 +311,72 @@ Wallet.prototype.fillPrevout = function fillPrevout(tx) {
 Wallet.prototype.fillTX = Wallet.prototype.fillPrevout;
 
 Wallet.prototype.scriptInputs = function scriptInputs(tx) {
-  var pub = this.getPublicKey();
-  var redeem = this.getScript();
-  var inputs = tx.inputs;
+  return this.addresses.reduce(function(total, address) {
+    var pub = address.getPublicKey();
+    var redeem = address.getScript();
+    tx.inputs.forEach(function(input, i) {
+      if (!input.prevout.tx && this.tx._all[input.prevout.hash])
+        input.prevout.tx = this.tx._all[input.prevout.hash];
 
-  inputs = inputs.filter(function(input, i) {
-    if (!input.prevout.tx && this.tx._all[input.prevout.hash])
-      input.prevout.tx = this.tx._all[input.prevout.hash];
+      if (!input.prevout.tx || !this.ownOutput(input.prevout.tx))
+        return;
 
-    if (!input.prevout.tx || !this.ownOutput(input.prevout.tx))
-      return false;
+      if (tx.scriptInput(i, pub, redeem))
+        total++;
+    }, this);
 
-    tx.scriptInput(i, pub, redeem);
-
-    return true;
-  }, this);
-
-  return inputs.length;
+    return total;
+  }, 0, this);
 };
 
 Wallet.prototype.signInputs = function signInputs(tx, type) {
-  var key = this.key;
-  var inputs = tx.inputs;
+  var self = this;
 
-  inputs = inputs.filter(function(input, i) {
-    if (!input.prevout.tx && this.tx._all[input.prevout.hash])
-      input.prevout.tx = this.tx._all[input.prevout.hash];
+  return this.addresses.reduce(function(total, address) {
+    if (!address.key.priv)
+      return total;
 
-    if (!input.prevout.tx || !this.ownOutput(input.prevout.tx))
-      return false;
+    tx.inputs.forEach(function(input, i) {
+      if (!input.prevout.tx && self.tx._all[input.prevout.hash])
+        input.prevout.tx = self.tx._all[input.prevout.hash];
 
-    tx.signInput(i, key, type);
+      if (!input.prevout.tx || !self.ownOutput(input.prevout.tx))
+        return;
 
-    return true;
-  }, this);
+      if (tx.signInput(i, address.key, type))
+        total++;
+    });
 
-  return inputs.length;
+    return total;
+  }, 0);
 };
 
 Wallet.prototype.sign = function sign(tx, type) {
-  var pub = this.getPublicKey();
-  var redeem = this.getScript();
-  var key = this.key;
-  var inputs = tx.inputs;
+  var self = this;
 
-  // Add signature script to each input
-  inputs = inputs.filter(function(input, i) {
-    if (!input.prevout.tx && this.tx._all[input.prevout.hash])
-      input.prevout.tx = this.tx._all[input.prevout.hash];
+  return this.addresses.reduce(function(total, address) {
+    var pub = address.getPublicKey();
+    var redeem = address.getScript();
+    var key = address.key;
 
-    // Filter inputs that this wallet own
-    if (!input.prevout.tx || !this.ownOutput(input.prevout.tx))
-      return false;
+    if (!key.priv)
+      return total;
 
-    tx.scriptSig(i, key, pub, redeem, type);
+    // Add signature script to each input
+    tx.inputs.forEach(function(input, i) {
+      if (!input.prevout.tx && self.tx._all[input.prevout.hash])
+        input.prevout.tx = self.tx._all[input.prevout.hash];
 
-    return true;
-  }, this);
+      // Filter inputs that this wallet own
+      if (!input.prevout.tx || !self.ownOutput(input.prevout.tx))
+        return;
 
-  return inputs.length;
+      if (tx.scriptSig(i, key, pub, redeem, type))
+        total++;
+    });
+
+    return total;
+  }, 0);
 };
 
 Wallet.prototype.addTX = function addTX(tx, block) {
@@ -647,82 +438,87 @@ Wallet.prototype.toAddress = function toAddress() {
 
 Wallet.prototype.toJSON = function toJSON(encrypt) {
   return {
-    v: 2,
+    v: 3,
     name: 'wallet',
     network: network.type,
-    encrypted: encrypt ? true : false,
     label: this.label,
-    address: this.getKeyAddress(),
-    scriptaddress: this.getScriptAddress(),
+    accountIndex: this.accountIndex,
+    addressIndex: this.addressIndex,
+    changeIndex: this.changeIndex,
+    addresses: this.addresses.filter(function(address) {
+      if (!address.hd)
+        return true;
+
+      if (address.change)
+        return false;
+
+      return true;
+    }).map(function(address) {
+      return address.toJSON(encrypt);
+    }),
     balance: utils.toBTC(this.getBalance()),
-    pub: this.getPublicKey('hex'),
-    priv: encrypt
-      ? encrypt(this.getPrivateKey('base58'))
-      : this.getPrivateKey('base58'),
-    xprivkey: this.hd
-      ? (encrypt ? encrypt(this.hd.xprivkey) : this.hd.xprivkey)
-      : null,
-    type: this.type,
-    subtype: this.subtype,
-    redeem: this.redeem ? utils.toHex(this.redeem) : null,
-    keys: this.keys.map(utils.toBase58),
-    m: this.m,
-    n: this.n,
     tx: this.tx.toJSON()
   };
 };
 
 Wallet.fromJSON = function fromJSON(json, decrypt) {
-  var priv, pub, xprivkey, multisig, compressed, key, w;
+  var priv, pub, xprivkey, multisig, compressed, key, w, i;
 
-  assert.equal(json.v, 2);
+  assert.equal(json.v, 3);
   assert.equal(json.name, 'wallet');
 
   if (json.network)
     assert.equal(json.network, network.type);
 
-  if (json.encrypted && !decrypt)
-    throw new Error('Cannot decrypt wallet');
-
-  if (json.priv) {
-    priv = json.priv;
-    if (json.encrypted)
-      priv = decrypt(priv);
-
-    key = Wallet.fromSecret(json.priv);
-    priv = key.priv;
-    compressed = key.compressed;
-  } else {
-    pub = bcoin.utils.toArray(json.pub, 'hex');
-    compressed = pub[0] !== 0x04;
-  }
-
-  if (json.xprivkey) {
-    xprivkey = json.xprivkey;
-    if (json.encrypted)
-      xprivkey = decrypt(xprivkey);
-    priv = bcoin.hd.priv(xprivkey);
-  }
-
   w = new Wallet({
     label: json.label,
-    priv: priv,
-    pub: pub,
-    compressed: compressed,
-    multisig: multisig,
-    type: json.type,
-    subtype: json.subtype,
-    redeem: json.redeem ? utils.toArray(json.redeem, 'hex') : null,
-    keys: json.keys.map(utils.fromBase58),
-    m: json.m,
-    n: json.n
+    accountIndex: json.accountIndex,
+    addressIndex: json.addressIndex,
+    changeIndex: json.changeIndex,
+    addresses: json.addresses.map(function(address) {
+      return bcoin.address.fromJSON(address, decrypt);
+    })
   });
 
   w.tx.fromJSON(json.tx);
 
+  // Make sure we have all the change
+  // addresses (we don't save them)
+  for (i = 0; i < w.changeIndex; i++) {
+    w.addKey({
+      change: true,
+      key: w.master.deriveChange(i, w.accountIndex)
+    });
+  }
+
   return w;
 };
 
+// Compat - Legacy
+Wallet.toSecret = function toSecret(priv, compressed) {
+  return bcoin.keypair.toSecret(priv, compressed);
+};
+
+Wallet.fromSecret = function fromSecret(priv) {
+  return bcoin.keypair.fromSecret(priv);
+};
+
+Wallet.key2hash = function key2hash(key) {
+  return bcoin.address.key2hash(key);
+};
+
+Wallet.hash2addr = function hash2addr(hash, prefix) {
+  return bcoin.address.hash2addr(hash, prefix);
+};
+
+Wallet.addr2hash = function addr2hash(addr, prefix) {
+  return bcoin.address.addr2hash(addr, prefix);
+};
+
+Wallet.validateAddress = function validateAddress(addr, prefix) {
+  return bcoin.address.validateAddress(addr, prefix);
+};
+
 /**
  * Expose
  */