diff --git a/Gruntfile.js b/Gruntfile.js
index 462a485f..a1b1bf5e 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -41,6 +41,7 @@ module.exports = function(grunt) {
           "src/js/sjcl-custom/sjcl-extramath.js",
           "src/js/sjcl-custom/sjcl-montgomery.js",
           "src/js/sjcl-custom/sjcl-validecc.js",
+          "src/js/sjcl-custom/sjcl-ecdsa-canonical.js",
           "src/js/sjcl-custom/sjcl-ecdsa-der.js",
           "src/js/sjcl-custom/sjcl-jacobi.js"
         ],
diff --git a/README.md b/README.md
index 9eb999f4..695bee1b 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,7 @@
 #The Ripple JavaScript Library
 
+[![NPM](https://nodei.co/npm/ripple-lib.png)](https://www.npmjs.org/package/ripple-lib)
+
 `ripple-lib` connects to the Ripple network via the WebSocket protocol and runs in Node.js as well as in the browser.
 
 **Use ripple-lib for**
diff --git a/build/sjcl.js b/build/sjcl.js
index 8e2c9a2a..b2c436dc 100644
--- a/build/sjcl.js
+++ b/build/sjcl.js
@@ -4043,6 +4043,24 @@ sjcl.ecc.ecdsa.publicKey.prototype = {
   }
 };
 
+sjcl.ecc.ecdsa.secretKey.prototype.canonicalizeSignature = function(rs) {
+  var w = sjcl.bitArray,
+      R = this._curve.r,
+      l = R.bitLength();
+
+  var r = sjcl.bn.fromBits(w.bitSlice(rs,0,l)),
+      s = sjcl.bn.fromBits(w.bitSlice(rs,l,2*l));
+
+  // For a canonical signature we want the lower of two possible values for s
+  // 0 < s <= n/2
+  if (!R.copy().halveM().greaterEquals(s)) {
+    s = R.sub(s);
+  }
+
+  return w.concat(r.toBits(l), s.toBits(l));
+};
+
+
 sjcl.ecc.ecdsa.secretKey.prototype.signDER = function(hash, paranoia) {
   return this.encodeDER(this.sign(hash, paranoia));
 };
diff --git a/src/js/ripple/amount.js b/src/js/ripple/amount.js
index d5dfc5ba..1d4440ad 100644
--- a/src/js/ripple/amount.js
+++ b/src/js/ripple/amount.js
@@ -71,8 +71,8 @@ Amount.from_json = function (j) {
   return (new Amount()).parse_json(j);
 };
 
-Amount.from_quality = function (q, c, i) {
-  return (new Amount()).parse_quality(q, c, i);
+Amount.from_quality = function (quality, currency, issuer, opts) {
+  return (new Amount()).parse_quality(quality, currency, issuer, opts);
 };
 
 Amount.from_human = function (j, opts) {
@@ -159,6 +159,29 @@ Amount.prototype.add = function (v) {
   return result;
 };
 
+/**
+ * Turn this amount into its inverse.
+ *
+ * @private
+ */
+Amount.prototype._invert = function () {
+  this._value = consts.bi_1e32.divide(this._value);
+  this._offset = -32 - this._offset;
+  this.canonicalize();
+
+  return this;
+};
+
+/**
+ * Return the inverse of this amount.
+ *
+ * @return {Amount} New Amount object with same currency and issuer, but the
+ *   inverse of the value.
+ */
+Amount.prototype.invert = function () {
+  return this.copy()._invert();
+};
+
 Amount.prototype.canonicalize = function () {
   if (!(this._value instanceof BigInteger)) {
     // NaN.
@@ -349,9 +372,14 @@ Amount.prototype.divide = function (d) {
  *
  * @this {Amount} The numerator (top half) of the fraction.
  * @param {Amount} denominator The denominator (bottom half) of the fraction.
+ * @param opts Options for the calculation.
+ * @param opts.reference_date {Date|Number} Date based on which demurrage/interest
+ *   should be applied. Can be given as JavaScript Date or int for Ripple epoch.
  * @return {Amount} The resulting ratio. Unit will be the same as numerator.
  */
-Amount.prototype.ratio_human = function (denominator) {
+Amount.prototype.ratio_human = function (denominator, opts) {
+  opts = opts || {};
+
   if (typeof denominator === 'number' && parseInt(denominator, 10) === denominator) {
     // Special handling of integer arguments
     denominator = Amount.from_json('' + denominator + '.0');
@@ -367,6 +395,14 @@ Amount.prototype.ratio_human = function (denominator) {
     return Amount.NaN();
   }
 
+  // Apply interest/demurrage
+  //
+  // We only need to apply it to the second factor, because the currency unit of
+  // the first factor will carry over into the result.
+  if (opts.reference_date) {
+    denominator = denominator.applyInterest(opts.reference_date);
+  }
+
   // Special case: The denominator is a native (XRP) amount.
   //
   // In that case, it's going to be expressed as base units (1 XRP =
@@ -402,9 +438,14 @@ Amount.prototype.ratio_human = function (denominator) {
  *
  * @this {Amount} The first factor of the product.
  * @param {Amount} factor The second factor of the product.
+ * @param opts Options for the calculation.
+ * @param opts.reference_date {Date|Number} Date based on which demurrage/interest
+ *   should be applied. Can be given as JavaScript Date or int for Ripple epoch.
  * @return {Amount} The product. Unit will be the same as the first factor.
  */
-Amount.prototype.product_human = function (factor) {
+Amount.prototype.product_human = function (factor, opts) {
+  opts = opts || {};
+
   if (typeof factor === 'number' && parseInt(factor, 10) === factor) {
     // Special handling of integer arguments
     factor = Amount.from_json(String(factor) + '.0');
@@ -417,6 +458,14 @@ Amount.prototype.product_human = function (factor) {
     return Amount.NaN();
   }
 
+  // Apply interest/demurrage
+  //
+  // We only need to apply it to the second factor, because the currency unit of
+  // the first factor will carry over into the result.
+  if (opts.reference_date) {
+    factor = factor.applyInterest(opts.reference_date);
+  }
+
   var product = this.multiply(factor);
 
   // Special case: The second factor is a native (XRP) amount expressed as base
@@ -618,17 +667,81 @@ Amount.prototype.parse_issuer = function (issuer) {
   return this;
 };
 
-// --> h: 8 hex bytes quality or 32 hex bytes directory index.
-Amount.prototype.parse_quality = function (q, c, i) {
+/**
+ * Decode a price from a BookDirectory index.
+ *
+ * BookDirectory ledger entries each encode the offer price in their index. This
+ * method can decode that information and populate an Amount object with it.
+ *
+ * It is possible not to provide a currency or issuer, but be aware that Amount
+ * objects behave differently based on the currency, so you may get incorrect
+ * results.
+ *
+ * Prices involving demurraging currencies are tricky, since they depend on the
+ * base and counter currencies.
+ *
+ * @param quality {String} 8 hex bytes quality or 32 hex bytes BookDirectory
+ *   index.
+ * @param counterCurrency {Currency|String} Currency of the resulting Amount
+ *   object.
+ * @param counterIssuer {Issuer|String} Issuer of the resulting Amount object.
+ * @param opts Additional options
+ * @param opts.inverse {Boolean} If true, return the inverse of the price
+ *   encoded in the quality.
+ * @param opts.base_currency {Currency|String} The other currency. This plays a
+ *   role with interest-bearing or demurrage currencies. In that case the
+ *   demurrage has to be applied when the quality is decoded, otherwise the
+ *   price will be false.
+ * @param opts.reference_date {Date|Number} Date based on which demurrage/interest
+ *   should be applied. Can be given as JavaScript Date or int for Ripple epoch.
+ * @param opts.xrp_as_drops {Boolean} Whether XRP amount should be treated as
+ *   drops. When the base currency is XRP, the quality is calculated in drops.
+ *   For human use however, we want to think of 1000000 drops as 1 XRP and
+ *   prices as per-XRP instead of per-drop.
+ */
+Amount.prototype.parse_quality = function (quality, counterCurrency, counterIssuer, opts)
+{
+  opts = opts || {};
+
+  var baseCurrency = Currency.from_json(opts.base_currency);
+
   this._is_negative = false;
-  this._value       = new BigInteger(q.substring(q.length-14), 16);
-  this._offset      = parseInt(q.substring(q.length-16, q.length-14), 16)-100;
-  this._currency    = Currency.from_json(c);
-  this._issuer      = UInt160.from_json(i);
+  this._value       = new BigInteger(quality.substring(quality.length-14), 16);
+  this._offset      = parseInt(quality.substring(quality.length-16, quality.length-14), 16)-100;
+  this._currency    = Currency.from_json(counterCurrency);
+  this._issuer      = UInt160.from_json(counterIssuer);
   this._is_native   = this._currency.is_native();
 
+  // Correct offset if xrp_as_drops option is not set and base currency is XRP
+  if (!opts.xrp_as_drops &&
+      baseCurrency.is_valid() &&
+      baseCurrency.is_native()) {
+    if (opts.inverse) {
+      this._offset -= 6;
+    } else {
+      this._offset += 6;
+    }
+  }
+
+  if (opts.inverse) {
+    this._invert();
+  }
+
   this.canonicalize();
 
+  if (opts.reference_date && baseCurrency.is_valid() && baseCurrency.has_interest()) {
+    var interest = baseCurrency.get_interest_at(opts.reference_date);
+
+    // XXX If we had better math utilities, we wouldn't need this hack.
+    var interestTempAmount = Amount.from_json(""+interest+"/1/1");
+
+    if (interestTempAmount.is_valid()) {
+      var v = this.divide(interestTempAmount);
+      this._value = v._value;
+      this._offset = v._offset;
+    }
+  }
+
   return this;
 }
 
@@ -850,6 +963,39 @@ Amount.prototype.to_text = function (allow_nan) {
   return result;
 };
 
+/**
+ * Calculate present value based on currency and a reference date.
+ *
+ * This only affects demurraging and interest-bearing currencies.
+ *
+ * User should not store amount objects after the interest is applied. This is
+ * intended by display functions such as toHuman().
+ *
+ * @param referenceDate {Date|Number} Date based on which demurrage/interest
+ *   should be applied. Can be given as JavaScript Date or int for Ripple epoch.
+ * @return {Amount} The amount with interest applied.
+ */
+Amount.prototype.applyInterest = function (referenceDate) {
+  if (this._currency.has_interest()) {
+    var interest = this._currency.get_interest_at(referenceDate);
+
+    // XXX Because the Amount parsing routines don't support some of the things
+    //     that JavaScript can output when casting a float to a string, the
+    //     following call sometimes does not produce a valid Amount.
+    //
+    //     The correct way to solve this is probably to switch to a proper
+    //     BigDecimal for our internal representation and then use that across
+    //     the board instead of instantiating these dummy Amount objects.
+    var interestTempAmount = Amount.from_json(""+interest+"/1/1");
+
+    if (interestTempAmount.is_valid()) {
+      return this.multiply(interestTempAmount);
+    }
+  } else {
+    return this;
+  }
+};
+
 /**
  * Format only value in a human-readable format.
  *
@@ -885,21 +1031,8 @@ Amount.prototype.to_human = function (opts) {
 
   // Apply demurrage/interest
   var ref = this;
-  if (opts.reference_date && this._currency.has_interest()) {
-    var interest = this._currency.get_interest_at(opts.reference_date);
-
-    // XXX Because the Amount parsing routines don't support some of the things
-    //     that JavaScript can output when casting a float to a string, the
-    //     following call sometimes does not produce a valid Amount.
-    //
-    //     The correct way to solve this is probably to switch to a proper
-    //     BigDecimal for our internal representation and then use that across
-    //     the board instead of instantiating these dummy Amount objects.
-    var interestTempAmount = Amount.from_json(""+interest+"/1/1");
-
-    if (interestTempAmount.is_valid()) {
-      ref = this.multiply(interestTempAmount);
-    }
+  if (opts.reference_date) {
+    ref = this.applyInterest(opts.reference_date);
   }
 
   var order         = ref._is_native ? consts.xns_precision : -ref._offset;
diff --git a/src/js/ripple/keypair.js b/src/js/ripple/keypair.js
index db82e79d..518ae70d 100644
--- a/src/js/ripple/keypair.js
+++ b/src/js/ripple/keypair.js
@@ -89,8 +89,10 @@ KeyPair.prototype.get_address = function () {
 };
 
 KeyPair.prototype.sign = function (hash) {
-  var hash = UInt256.from_json(hash);
-  return this._secret.signDER(hash.to_bits(), 0);
+  hash = UInt256.from_json(hash);
+  var sig = this._secret.sign(hash.to_bits(), 0);
+  sig = this._secret.canonicalizeSignature(sig);
+  return this._secret.encodeDER(sig);
 };
 
 exports.KeyPair = KeyPair;
diff --git a/src/js/ripple/orderbook.js b/src/js/ripple/orderbook.js
index d51f3e72..d667289b 100644
--- a/src/js/ripple/orderbook.js
+++ b/src/js/ripple/orderbook.js
@@ -225,11 +225,12 @@ OrderBook.prototype.notify = function (message) {
         break;
 
       case 'CreatedNode':
-        var price = Amount.from_json(an.fields.TakerPays).ratio_human(an.fields.TakerGets);
+        // XXX Should use Amount#from_quality
+        var price = Amount.from_json(an.fields.TakerPays).ratio_human(an.fields.TakerGets, {reference_date: new Date()});
 
         for (i = 0, l = self._offers.length; i < l; i++) {
           offer = self._offers[i];
-          var priceItem = Amount.from_json(offer.TakerPays).ratio_human(offer.TakerGets);
+          var priceItem = Amount.from_json(offer.TakerPays).ratio_human(offer.TakerGets, {reference_date: new Date()});
 
           if (price.compareTo(priceItem) <= 0) {
             var obj   = an.fields;
diff --git a/src/js/ripple/server.js b/src/js/ripple/server.js
index 1b393503..f7846e86 100644
--- a/src/js/ripple/server.js
+++ b/src/js/ripple/server.js
@@ -36,8 +36,17 @@ function Server(remote, opts) {
     throw new Error('Server host is malformed, use "host" and "port" server configuration');
   }
 
-  if (typeof opts.port !== 'number') {
-    throw new TypeError('Server configuration "port" is not a Number');
+  // We want to allow integer strings as valid port numbers for backward
+  // compatibility.
+  if (typeof opts.port === 'string') {
+    opts.port = parseFloat(opts.port);
+  }
+
+  if (typeof opts.port !== 'number' ||
+      opts.port >>> 0 !== parseFloat(opts.port) || // is integer?
+      opts.port < 1 ||
+      opts.port > 65535) {
+    throw new TypeError('Server "port" must be an integer in range 1-65535');
   }
 
   if (typeof opts.secure !== 'boolean') {
diff --git a/src/js/ripple/transaction.js b/src/js/ripple/transaction.js
index 58dcc131..f50b74ab 100644
--- a/src/js/ripple/transaction.js
+++ b/src/js/ripple/transaction.js
@@ -73,22 +73,19 @@ function Transaction(remote) {
   // Index at which transaction was submitted
   this.submitIndex = void(0);
 
+  this.canonical = true;
+
   // We aren't clever enough to eschew preventative measures so we keep an array
   // of all submitted transactionIDs (which can change due to load_factor
   // effecting the Fee amount). This should be populated with a transactionID
   // any time it goes on the network
-  this.submittedIDs = [ ]
+  this.submittedIDs = [ ];
 
   function finalize(message) {
-    if (self.result) {
-      self.result.ledger_index = message.ledger_index;
-      self.result.ledger_hash  = message.ledger_hash;
-    } else {
-      self.result = message;
-      self.result.tx_json = self.tx_json;
+    if (!self.finalized) {
+      self.finalized = true;
+      self.emit('cleanup', message);
     }
-
-    self.emit('cleanup', message);
   };
 
   this.once('success', function(message) {
@@ -120,6 +117,11 @@ Transaction.fee_units = {
 };
 
 Transaction.flags = {
+  // Universal flags can apply to any transaction type
+  Universal: {
+    FullyCanonicalSig:  0x80000000
+  },
+
   AccountSet: {
     RequireDestTag:     0x00010000,
     OptionalDestTag:    0x00020000,
@@ -278,6 +280,15 @@ Transaction.prototype.complete = function() {
     this.tx_json.SigningPubKey = key.to_hex_pub();
   }
 
+  // Set canonical flag - this enables canonicalized signature checking
+  if (this.canonical) {
+    this.tx_json.Flags |= Transaction.flags.Universal.FullyCanonicalSig;
+
+    // JavaScript converts operands to 32-bit signed ints before doing bitwise
+    // operations. We need to convert it back to an unsigned int.
+    this.tx_json.Flags = this.tx_json.Flags >>> 0;
+  }
+
   return this.tx_json;
 };
 
diff --git a/src/js/sjcl-custom/sjcl-ecdsa-canonical.js b/src/js/sjcl-custom/sjcl-ecdsa-canonical.js
new file mode 100644
index 00000000..d56c5114
--- /dev/null
+++ b/src/js/sjcl-custom/sjcl-ecdsa-canonical.js
@@ -0,0 +1,17 @@
+sjcl.ecc.ecdsa.secretKey.prototype.canonicalizeSignature = function(rs) {
+  var w = sjcl.bitArray,
+      R = this._curve.r,
+      l = R.bitLength();
+
+  var r = sjcl.bn.fromBits(w.bitSlice(rs,0,l)),
+      s = sjcl.bn.fromBits(w.bitSlice(rs,l,2*l));
+
+  // For a canonical signature we want the lower of two possible values for s
+  // 0 < s <= n/2
+  if (!R.copy().halveM().greaterEquals(s)) {
+    s = R.sub(s);
+  }
+
+  return w.concat(r.toBits(l), s.toBits(l));
+};
+
diff --git a/test/amount-test.js b/test/amount-test.js
index 51c40282..0630470c 100644
--- a/test/amount-test.js
+++ b/test/amount-test.js
@@ -431,4 +431,130 @@ describe('Amount', function() {
       assert.strictEqual(a.not_equals_why(b), 'Native mismatch.');
     });
   });
+
+  describe('product_human', function() {
+    it('Multiply 0 XRP with 0 XRP', function () {
+      assert.strictEqual('0/XRP', Amount.from_json('0').product_human(Amount.from_json('0')).to_text_full());
+    });
+    it('Multiply 0 USD with 0 XRP', function () {
+      assert.strictEqual('0/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh', Amount.from_json('0/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').product_human(Amount.from_json('0')).to_text_full());
+    });
+    it('Multiply 0 XRP with 0 USD', function () {
+      assert.strictEqual('0/XRP', Amount.from_json('0').product_human(Amount.from_json('0/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
+    });
+    it('Multiply 1 XRP with 0 XRP', function () {
+      assert.strictEqual('0/XRP', Amount.from_json('1').product_human(Amount.from_json('0')).to_text_full());
+    });
+    it('Multiply 1 USD with 0 XRP', function () {
+      assert.strictEqual('0/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh', Amount.from_json('1/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').product_human(Amount.from_json('0')).to_text_full());
+    });
+    it('Multiply 1 XRP with 0 USD', function () {
+      assert.strictEqual('0/XRP', Amount.from_json('1').product_human(Amount.from_json('0/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
+    });
+    it('Multiply 0 XRP with 1 XRP', function () {
+      assert.strictEqual('0/XRP', Amount.from_json('0').product_human(Amount.from_json('1')).to_text_full());
+    });
+    it('Multiply 0 USD with 1 XRP', function () {
+      assert.strictEqual('0/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh', Amount.from_json('0/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').product_human(Amount.from_json('1')).to_text_full());
+    });
+    it('Multiply 0 XRP with 1 USD', function () {
+      assert.strictEqual('0/XRP', Amount.from_json('0').product_human(Amount.from_json('1/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
+    });
+    it('Multiply XRP with USD', function () {
+      assert.equal('0.002/XRP', Amount.from_json('200').product_human(Amount.from_json('10/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
+    });
+    it('Multiply XRP with USD', function () {
+      assert.strictEqual('0.2/XRP', Amount.from_json('20000').product_human(Amount.from_json('10/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
+    });
+    it('Multiply XRP with USD', function () {
+      assert.strictEqual('20/XRP', Amount.from_json('2000000').product_human(Amount.from_json('10/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
+    });
+    it('Multiply XRP with USD, neg', function () {
+      assert.strictEqual('-0.002/XRP', Amount.from_json('200').product_human(Amount.from_json('-10/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
+    });
+    it('Multiply XRP with USD, neg, frac', function () {
+      assert.strictEqual('-0.222/XRP', Amount.from_json('-6000').product_human(Amount.from_json('37/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
+    });
+    it('Multiply USD with USD', function () {
+      assert.strictEqual('20000/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh', Amount.from_json('2000/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').product_human(Amount.from_json('10/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
+    });
+    it('Multiply USD with USD', function () {
+      assert.strictEqual('200000000000/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh', Amount.from_json('2000000/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').product_human(Amount.from_json('100000/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
+    });
+    it('Multiply EUR with USD, result < 1', function () {
+      assert.strictEqual('100000/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh', Amount.from_json('100/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').product_human(Amount.from_json('1000/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
+    });
+    it('Multiply EUR with USD, neg', function () {
+      assert.strictEqual(Amount.from_json('-24000/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').product_human(Amount.from_json('2000/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full(), '-48000000/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
+    });
+    it('Multiply EUR with USD, neg, <1', function () {
+      assert.strictEqual(Amount.from_json('0.1/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').product_human(Amount.from_json('-1000/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full(), '-100/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
+    });
+    it('Multiply EUR with XRP, factor < 1', function () {
+      assert.strictEqual(Amount.from_json('0.05/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').product_human(Amount.from_json('2000')).to_text_full(), '0.0001/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
+    });
+    it('Multiply EUR with XRP, neg', function () {
+      assert.strictEqual(Amount.from_json('-100/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').product_human(Amount.from_json('5')).to_text_full(), '-0.0005/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
+    });
+    it('Multiply EUR with XRP, neg, <1', function () {
+      assert.strictEqual(Amount.from_json('-0.05/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').product_human(Amount.from_json('2000')).to_text_full(), '-0.0001/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
+    });
+    it('Multiply XRP with XRP', function () {
+      assert.strictEqual(Amount.from_json('10000000').product_human(Amount.from_json('10')).to_text_full(), '0.0001/XRP');
+    });
+    it('Multiply USD with XAU (dem)', function () {
+      assert.strictEqual(Amount.from_json('2000/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').product_human(Amount.from_json('10/015841551A748AD2C1F76FF6ECB0CCCD00000000/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh'), {reference_date: 443845330 + 31535000}).to_text_full(), '19900.00316303882/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
+    });
+  });
+
+  describe('ratio_human', function() {
+    it('Divide USD by XAU (dem)', function () {
+      assert.strictEqual(Amount.from_json('2000/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').ratio_human(Amount.from_json('10/015841551A748AD2C1F76FF6ECB0CCCD00000000/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh'), {reference_date: 443845330 + 31535000}).to_text_full(), '201.0049931765529/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
+    });
+  });
+
+  describe('_invert', function() {
+    it('Invert 1', function () {
+      assert.strictEqual(Amount.from_json('1/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').invert().to_text_full(), '1/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
+    });
+    it('Invert 20', function () {
+      assert.strictEqual(Amount.from_json('20/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').invert().to_text_full(), '0.05/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
+    });
+    it('Invert 0.02', function () {
+      assert.strictEqual(Amount.from_json('0.02/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').invert().to_text_full(), '50/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
+    });
+  });
+
+  describe('from_quality', function() {
+    it('BTC/XRP', function () {
+      assert.strictEqual(Amount.from_quality('7B73A610A009249B0CC0D4311E8BA7927B5A34D86634581C5F0FF9FF678E1000', 'XRP', NaN, {base_currency: 'BTC'}).to_text_full(), '44,970/XRP');
+    });
+    it('BTC/XRP inverse', function () {
+      assert.strictEqual(Amount.from_quality('37AAC93D336021AE94310D0430FFA090F7137C97D473488C4A0918D0DEF8624E', 'XRP', NaN, {inverse: true, base_currency: 'BTC'}).to_text_full(), '39,053.954453/XRP');
+    });
+    it('XRP/USD', function () {
+      assert.strictEqual(Amount.from_quality('DFA3B6DDAB58C7E8E5D944E736DA4B7046C30E4F460FD9DE4D05DCAA8FE12000', 'USD', 'rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B', {base_currency: 'XRP'}).to_text_full(), '0.0165/USD/rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B');
+    });
+    it('XRP/USD inverse', function () {
+      assert.strictEqual(Amount.from_quality('4627DFFCFF8B5A265EDBD8AE8C14A52325DBFEDAF4F5C32E5C22A840E27DCA9B', 'USD', 'rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B', {inverse: true, base_currency: 'XRP'}).to_text_full(), '0.010251/USD/rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B');
+    });
+    it('BTC/USD', function () {
+      assert.strictEqual(Amount.from_quality('6EAB7C172DEFA430DBFAD120FDC373B5F5AF8B191649EC9858038D7EA4C68000', 'USD', 'rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B', {base_currency: 'BTC'}).to_text_full(), '1000/USD/rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B');
+    });
+    it('BTC/USD inverse', function () {
+      assert.strictEqual(Amount.from_quality('20294C923E80A51B487EB9547B3835FD483748B170D2D0A455071AFD498D0000', 'USD', 'rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B', {inverse: true, base_currency: 'BTC'}).to_text_full(), '0.5/USD/rvYAfWj5gh67oV6fW32ZzP3Aw4Eubs59B');
+    });
+    it('XAU(dem)/XRP', function () {
+      assert.strictEqual(Amount.from_quality('587322CCBDE0ABD01704769A73A077C32FB39057D813D4165F1FF973CAF997EF', 'XRP', NaN, {base_currency: '015841551A748AD2C1F76FF6ECB0CCCD00000000', reference_date: 443845330 + 31535000}).to_text_full(), '90,452.246928/XRP');
+    });
+    it('XAU(dem)/XRP inverse', function () {
+      assert.strictEqual(Amount.from_quality('F72C7A9EAE4A45ED1FB547AD037D07B9B965C6E662BEBAFA4A03F2A976804235', 'XRP', NaN, {inverse: true, base_currency: '015841551A748AD2C1F76FF6ECB0CCCD00000000', reference_date: 443845330 + 31535000}).to_text_full(), '90,442.196677/XRP');
+    });
+    it('USD/XAU(dem)', function () {
+      assert.strictEqual(Amount.from_quality('4743E58E44974B325D42FD2BB683A6E36950F350EE46DD3A521B644B99782F5F', '015841551A748AD2C1F76FF6ECB0CCCD00000000', 'rUyPiNcSFFj6uMR2gEaD8jUerQ59G1qvwN', {base_currency: 'USD', reference_date: 443845330 + 31535000}).to_text_full(), '0.007710100231303007/015841551A748AD2C1F76FF6ECB0CCCD00000000/rUyPiNcSFFj6uMR2gEaD8jUerQ59G1qvwN');
+    });
+    it('USD/XAU(dem) inverse', function () {
+      assert.strictEqual(Amount.from_quality('CDFD3AFB2F8C5DBEF75B081F7C957FF5509563266F28F36C5704A0FB0BAD8800', '015841551A748AD2C1F76FF6ECB0CCCD00000000', 'rUyPiNcSFFj6uMR2gEaD8jUerQ59G1qvwN', {inverse: true, base_currency: 'USD', reference_date: 443845330 + 31535000}).to_text_full(), '0.007675186123263489/015841551A748AD2C1F76FF6ECB0CCCD00000000/rUyPiNcSFFj6uMR2gEaD8jUerQ59G1qvwN');
+    });
+  });
 });
diff --git a/test/sjcl-ecdsa-canonical-test.js b/test/sjcl-ecdsa-canonical-test.js
new file mode 100644
index 00000000..d0a270b7
--- /dev/null
+++ b/test/sjcl-ecdsa-canonical-test.js
@@ -0,0 +1,28 @@
+var assert = require('assert');
+var utils  = require('./testutils');
+var sjcl   = require('../build/sjcl');
+var Seed   = require('../src/js/ripple/seed').Seed;
+
+describe('SJCL ECDSA Canonicalization', function() {
+  describe('canonicalizeSignature', function() {
+    it('should canonicalize non-canonical signatures', function () {
+      var seed = Seed.from_json('saESc82Vun7Ta5EJRzGJbrXb5HNYk');
+      var key = seed.get_key('rBZ4j6MsoctipM6GEyHSjQKzXG3yambDnZ');
+
+      var rs = sjcl.codec.hex.toBits("27ce1b914045ba7e8c11a2f2882cb6e07a19d4017513f12e3e363d71dc3fff0fb0a0747ecc7b4ca46e45b3b32b6b2a066aa0249c027ef11e5bce93dab756549c");
+      rs = sjcl.ecc.ecdsa.secretKey.prototype.canonicalizeSignature.call(key._secret, rs);
+      assert.strictEqual(sjcl.codec.hex.fromBits(rs), "27ce1b914045ba7e8c11a2f2882cb6e07a19d4017513f12e3e363d71dc3fff0f4f5f8b813384b35b91ba4c4cd494d5f8500eb84aacc9af1d6403cab218dfeca5");
+    });
+
+    it('should not touch canonical signatures', function () {
+      var seed = Seed.from_json('saESc82Vun7Ta5EJRzGJbrXb5HNYk');
+      var key = seed.get_key('rBZ4j6MsoctipM6GEyHSjQKzXG3yambDnZ');
+
+      var rs = sjcl.codec.hex.toBits("5c32bc2b4d34e27af9fb66eeea0f47f6afb3d433658af0f649ebae7b872471ab7d23860688aaf9d8131f84cfffa6c56bf9c32fd8b315b2ef9d6bcb243f7a686c");
+      rs = sjcl.ecc.ecdsa.secretKey.prototype.canonicalizeSignature.call(key._secret, rs);
+      assert.strictEqual(sjcl.codec.hex.fromBits(rs), "5c32bc2b4d34e27af9fb66eeea0f47f6afb3d433658af0f649ebae7b872471ab7d23860688aaf9d8131f84cfffa6c56bf9c32fd8b315b2ef9d6bcb243f7a686c");
+    });
+  });
+});
+
+// vim:sw=2:sts=2:ts=8:et