diff --git a/lib/bcoin/chaindb.js b/lib/bcoin/chaindb.js
index 49f110cc..4eab67fe 100644
--- a/lib/bcoin/chaindb.js
+++ b/lib/bcoin/chaindb.js
@@ -8,17 +8,19 @@
 /*
  * Database Layout:
  *   R -> tip hash
- *   e/[hash] -> entry
- *   h/[hash] -> height
- *   H/[height] -> hash
- *   n/[hash] -> next hash
- *   b/[hash] -> block
- *   t/[hash] -> extended tx
- *   c/[hash]/[index] -> coin
- *   u/[hash] -> undo coins
- *   T/[address]/[hash] -> dummy (tx by address)
- *   C/[address]/[hash] -> dummy (coin by address)
- *   q/[height] -> block hash to be pruned
+ *   e[hash] -> entry
+ *   h[hash] -> height
+ *   H[height] -> hash
+ *   n[hash] -> next hash
+ *   b[hash] -> block
+ *   t[hash] -> extended tx
+ *   c[hash] -> coins
+ *   u[hash] -> undo coins
+ *   T[addr-hash][hash] -> dummy (tx by address)
+ *   C[addr-hash][hash][index] -> dummy (coin by address)
+ *   A[witaddr-hash][hash] -> dummy (tx by address)
+ *   B[witaddr-hash][hash][index] -> dummy (coin by address)
+ *   q[height] -> block hash to be pruned
  */
 
 var bcoin = require('./env');
@@ -35,108 +37,120 @@ var Parser = bcoin.protocol.parser;
 
 var layout = {
   R: function R() {
-    var p = new BufferWriter();
-    p.writeU8(0x52); // R
+    var key = new BufferWriter();
+    key.writeU8(0x52); // R
+    key = key.render();
     if (utils.isBrowser)
-      return p.render().toString('hex');
-    return p.render();
+      key = key.toString('hex');
+    return key;
   },
   e: function e(hash) {
-    var p = new BufferWriter();
-    p.writeU8(0x65); // e
-    p.writeHash(hash);
+    var key = new BufferWriter();
+    key.writeU8(0x65); // e
+    key.writeHash(hash);
+    key = key.render();
     if (utils.isBrowser)
-      return p.render().toString('hex');
-    return p.render();
+      key = key.toString('hex');
+    return key;
   },
   h: function h(hash) {
-    var p = new BufferWriter();
-    p.writeU8(0x68); // h
-    p.writeHash(hash);
+    var key = new BufferWriter();
+    key.writeU8(0x68); // h
+    key.writeHash(hash);
+    key = key.render();
     if (utils.isBrowser)
-      return p.render().toString('hex');
-    return p.render();
+      key = key.toString('hex');
+    return key;
   },
   H: function H(height) {
-    var p = new BufferWriter();
-    p.writeU8(0x48); // H
-    p.writeU32(height);
+    var key = new BufferWriter();
+    key.writeU8(0x48); // H
+    key.writeU32(height);
+    key = key.render();
     if (utils.isBrowser)
-      return p.render().toString('hex');
-    return p.render();
+      key = key.toString('hex');
+    return key;
   },
   n: function n(hash) {
-    var p = new BufferWriter();
-    p.writeU8(0x6e); // n
-    p.writeHash(hash);
+    var key = new BufferWriter();
+    key.writeU8(0x6e); // n
+    key.writeHash(hash);
+    key = key.render();
     if (utils.isBrowser)
-      return p.render().toString('hex');
-    return p.render();
+      key = key.toString('hex');
+    return key;
   },
   b: function b(hash) {
-    var p = new BufferWriter();
-    p.writeU8(0x62); // b
-    p.writeHash(hash);
+    var key = new BufferWriter();
+    key.writeU8(0x62); // b
+    key.writeHash(hash);
+    key = key.render();
     if (utils.isBrowser)
-      return p.render().toString('hex');
-    return p.render();
+      key = key.toString('hex');
+    return key;
   },
   t: function t(hash) {
-    var p = new BufferWriter();
-    p.writeU8(0x74); // t
-    p.writeHash(hash);
+    var key = new BufferWriter();
+    key.writeU8(0x74); // t
+    key.writeHash(hash);
+    key = key.render();
     if (utils.isBrowser)
-      return p.render().toString('hex');
-    return p.render();
+      key = key.toString('hex');
+    return key;
   },
   c: function c(hash) {
-    var p = new BufferWriter();
-    p.writeU8(0x63); // c
-    p.writeHash(hash);
+    var key = new BufferWriter();
+    key.writeU8(0x63); // c
+    key.writeHash(hash);
+    key = key.render();
     if (utils.isBrowser)
-      return p.render().toString('hex');
-    return p.render();
+      key = key.toString('hex');
+    return key;
   },
   u: function u(hash) {
-    var p = new BufferWriter();
-    p.writeU8(0x75); // u
-    p.writeHash(hash);
+    var key = new BufferWriter();
+    key.writeU8(0x75); // u
+    key.writeHash(hash);
+    key = key.render();
     if (utils.isBrowser)
-      return p.render().toString('hex');
-    return p.render();
+      key = key.toString('hex');
+    return key;
   },
   q: function q(height) {
-    var p = new BufferWriter();
-    p.writeU8(0x71); // q
-    p.writeU32(height);
+    var key = new BufferWriter();
+    key.writeU8(0x71); // q
+    key.writeU32(height);
+    key = key.render();
     if (utils.isBrowser)
-      return p.render().toString('hex');
-    return p.render();
+      key = key.toString('hex');
+    return key;
   },
   T: function T(address, hash) {
-    var p = new BufferWriter();
+    var key = new BufferWriter();
     if (address.length === 64)
-      p.writeU8(0x41); // A
+      key.writeU8(0x41); // A
     else
-      p.writeU8(0x54); // T
-    p.writeHash(address);
-    p.writeHash(hash);
+      key.writeU8(0x54); // T
+    key.writeHash(address);
+    key.writeHash(hash);
+    key = key.render();
     if (utils.isBrowser)
-      return p.render().toString('hex');
-    return p.render();
+      key = key.toString('hex');
+    return key;
   },
   C: function C(address, hash, index) {
-    var p = new BufferWriter();
+    var key = new BufferWriter();
     if (address.length === 64)
-      p.writeU8(0x42); // B
+      key.writeU8(0x42); // B
     else
-      p.writeU8(0x43); // C
-    p.writeHash(address);
-    p.writeHash(hash);
-    p.writeU32(index);
+      key.writeU8(0x43); // C
+    key.writeHash(address);
+    key.writeHash(hash);
+    key.writeU32(index);
+    key = key.render();
     if (utils.isBrowser)
-      return p.render().toString('hex');
-    return p.render();
+      key = key.toString('hex');
+    return key;
   },
   Cc: function Cc(key) {
     var hash, index;
@@ -1223,7 +1237,7 @@ ChainDB.prototype.getCoinsByAddress = function getCoinsByAddress(addresses, call
       return next();
 
     self.db.iterate({
-      gte: layout.C(address, constants.NULL_HASH, 0),
+      gte: layout.C(address, constants.ZERO_HASH, 0),
       lte: layout.C(address, constants.MAX_HASH, 0xffffffff),
       keyAsBuffer: !utils.isBrowser,
       transform: layout.Cc
@@ -1273,7 +1287,7 @@ ChainDB.prototype.getTXByAddress = function getTXByAddress(addresses, callback)
       return next();
 
     self.db.lookup({
-      gte: layout.T(address, constants.NULL_HASH),
+      gte: layout.T(address, constants.ZERO_HASH),
       lte: layout.T(address, constants.MAX_HASH),
       keyAsBuffer: !utils.isBrowser,
       transform: function(key) {
diff --git a/lib/bcoin/protocol/constants.js b/lib/bcoin/protocol/constants.js
index 8fcf5481..dcecb689 100644
--- a/lib/bcoin/protocol/constants.js
+++ b/lib/bcoin/protocol/constants.js
@@ -588,6 +588,17 @@ exports.ZERO_HASH = new Buffer(
   'hex'
 );
 
+/**
+ * A hash of all 0xff.
+ * @const {Buffer}
+ * @default
+ */
+
+exports.MAX_HASH = new Buffer(
+  'ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff',
+  'hex'
+);
+
 /**
  * A hash of all zeroes.
  * @const {String}
@@ -597,15 +608,6 @@ exports.ZERO_HASH = new Buffer(
 exports.NULL_HASH =
   '0000000000000000000000000000000000000000000000000000000000000000';
 
-/**
- * A hash of all 0xff.
- * @const {String}
- * @default
- */
-
-exports.MAX_HASH =
-  'ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff';
-
 /**
  * BCoin version.
  * @const {String}