diff --git a/src/api.js b/src/api.js
index 0aeb2b04cc..a243cfbadd 100644
--- a/src/api.js
+++ b/src/api.js
@@ -57,6 +57,10 @@ const errors = require('./common').errors
 const generateAddress =
   require('./offline/generate-address').generateAddressAPI
 const computeLedgerHash = require('./offline/ledgerhash')
+const signMessage =
+  require('./offline/sign-message')
+const verifyMessage =
+  require('./offline/verify-message')
 const signPaymentChannelClaim =
   require('./offline/sign-payment-channel-claim')
 const verifyPaymentChannelClaim =
@@ -152,6 +156,8 @@ _.assign(RippleAPI.prototype, {
 
   generateAddress,
   computeLedgerHash,
+  signMessage,
+  verifyMessage,
   signPaymentChannelClaim,
   verifyPaymentChannelClaim,
   errors
diff --git a/src/common/index.js b/src/common/index.js
index c79d69022b..e2b179177b 100644
--- a/src/common/index.js
+++ b/src/common/index.js
@@ -18,5 +18,7 @@ module.exports = {
     utils.convertKeysFromSnakeCaseToCamelCase,
   iso8601ToRippleTime: utils.iso8601ToRippleTime,
   rippleTimeToISO8601: utils.rippleTimeToISO8601,
-  isValidSecret: utils.isValidSecret
+  isValidSecret: utils.isValidSecret,
+  stringToUtf8ByteArray: utils.stringToUtf8ByteArray,
+  bytesToHex: utils.bytesToHex
 }
diff --git a/src/common/schema-validator.js b/src/common/schema-validator.js
index 1ad314ff46..8786a94c87 100644
--- a/src/common/schema-validator.js
+++ b/src/common/schema-validator.js
@@ -22,6 +22,7 @@ function loadSchemas() {
     require('./schemas/objects/max-adjustment.json'),
     require('./schemas/objects/memo.json'),
     require('./schemas/objects/memos.json'),
+    require('./schemas/objects/message.json'),
     require('./schemas/objects/public-key.json'),
     require('./schemas/objects/uint32.json'),
     require('./schemas/objects/value.json'),
@@ -77,6 +78,8 @@ function loadSchemas() {
     require('./schemas/output/get-transaction.json'),
     require('./schemas/output/get-transactions.json'),
     require('./schemas/output/get-trustlines.json'),
+    require('./schemas/output/sign-message.json'),
+    require('./schemas/output/verify-message.json'),
     require('./schemas/output/sign-payment-channel-claim.json'),
     require('./schemas/output/verify-payment-channel-claim.json'),
     require('./schemas/input/get-balances.json'),
@@ -107,6 +110,8 @@ function loadSchemas() {
     require('./schemas/input/sign.json'),
     require('./schemas/input/submit.json'),
     require('./schemas/input/generate-address.json'),
+    require('./schemas/input/sign-message.json'),
+    require('./schemas/input/verify-message.json'),
     require('./schemas/input/sign-payment-channel-claim.json'),
     require('./schemas/input/verify-payment-channel-claim.json'),
     require('./schemas/input/combine.json')
diff --git a/src/common/schemas/input/sign-message.json b/src/common/schemas/input/sign-message.json
new file mode 100644
index 0000000000..78b7e266b0
--- /dev/null
+++ b/src/common/schemas/input/sign-message.json
@@ -0,0 +1,17 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "title": "signMessageParameters",
+  "type": "object",
+  "properties": {
+    "message": {
+      "$ref": "message",
+      "description": "Message text."
+    },
+    "privateKey": {
+      "$ref": "publicKey",
+      "description": "The private key to sign the payment channel claim."
+    }
+  },
+  "additionalProperties": false,
+  "required": ["message", "privateKey"]
+}
diff --git a/src/common/schemas/input/verify-message.json b/src/common/schemas/input/verify-message.json
new file mode 100644
index 0000000000..30674a7399
--- /dev/null
+++ b/src/common/schemas/input/verify-message.json
@@ -0,0 +1,21 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "title": "verifyMessageParameters",
+  "type": "object",
+  "properties": {
+    "message": {
+      "$ref": "message",
+      "description": "Message text."
+    },
+    "signature": {
+      "$ref": "signature",
+      "description": "Signature of this message."
+    },
+    "publicKey": {
+      "$ref": "publicKey",
+      "description": "Public key of the message's sender"
+    }
+  },
+  "additionalProperties": false,
+  "required": ["message", "signature", "publicKey"]
+}
diff --git a/src/common/schemas/objects/message.json b/src/common/schemas/objects/message.json
new file mode 100644
index 0000000000..a7c30f6755
--- /dev/null
+++ b/src/common/schemas/objects/message.json
@@ -0,0 +1,7 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "title": "message",
+  "description": "Message objects represent arbitrary data that can be signed",
+  "type": "string",
+  "additionalProperties": false
+}
diff --git a/src/common/schemas/output/sign-message.json b/src/common/schemas/output/sign-message.json
new file mode 100644
index 0000000000..67467e0ed8
--- /dev/null
+++ b/src/common/schemas/output/sign-message.json
@@ -0,0 +1,7 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "title": "signMessage",
+  "type": "string",
+  "$ref": "signature",
+  "additionalProperties": false
+}
diff --git a/src/common/schemas/output/verify-message.json b/src/common/schemas/output/verify-message.json
new file mode 100644
index 0000000000..dedf464eb6
--- /dev/null
+++ b/src/common/schemas/output/verify-message.json
@@ -0,0 +1,6 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "title": "verifyMessage",
+  "type": "boolean",
+  "additionalProperties": false
+}
diff --git a/src/common/utils.js b/src/common/utils.js
index cf806a4cd6..a7c001c438 100644
--- a/src/common/utils.js
+++ b/src/common/utils.js
@@ -81,6 +81,46 @@ function iso8601ToRippleTime(iso8601: string): number {
   return unixToRippleTimestamp(Date.parse(iso8601))
 }
 
+/**
+ * Converts a JS string to a UTF-8 "byte" array.
+ * From {@link https://git.io/v52py|Google's common JavaScript library}.
+ * @param {string} str 16-bit unicode string.
+ * @return {!Array<number>} UTF-8 byte array.
+ */
+function stringToUtf8ByteArray(str) {
+  var out = [], p = 0;
+  for (var i = 0; i < str.length; i++) {
+    var c = str.charCodeAt(i);
+    if (c < 128) {
+      out[p++] = c;
+    } else if (c < 2048) {
+      out[p++] = (c >> 6) | 192;
+      out[p++] = (c & 63) | 128;
+    } else if (
+        ((c & 0xFC00) == 0xD800) && (i + 1) < str.length &&
+        ((str.charCodeAt(i + 1) & 0xFC00) == 0xDC00)) {
+      // Surrogate Pair
+      c = 0x10000 + ((c & 0x03FF) << 10) + (str.charCodeAt(++i) & 0x03FF);
+      out[p++] = (c >> 18) | 240;
+      out[p++] = ((c >> 12) & 63) | 128;
+      out[p++] = ((c >> 6) & 63) | 128;
+      out[p++] = (c & 63) | 128;
+    } else {
+      out[p++] = (c >> 12) | 224;
+      out[p++] = ((c >> 6) & 63) | 128;
+      out[p++] = (c & 63) | 128;
+    }
+  }
+  return out;
+}
+
+function bytesToHex(a) {
+  return a.map(function(byteValue) {
+    const hex = byteValue.toString(16).toUpperCase();
+    return hex.length > 1 ? hex : '0' + hex;
+  }).join('');
+}
+
 module.exports = {
   dropsToXrp,
   xrpToDrops,
@@ -89,5 +129,7 @@ module.exports = {
   removeUndefined,
   rippleTimeToISO8601,
   iso8601ToRippleTime,
-  isValidSecret
+  isValidSecret,
+  stringToUtf8ByteArray,
+  bytesToHex
 }
diff --git a/src/common/validate.js b/src/common/validate.js
index 53f6f3a6d4..b15e33668a 100644
--- a/src/common/validate.js
+++ b/src/common/validate.js
@@ -58,6 +58,10 @@ module.exports = {
   submit: _.partial(schemaValidate, 'submitParameters'),
   computeLedgerHash: _.partial(schemaValidate, 'computeLedgerHashParameters'),
   generateAddress: _.partial(schemaValidate, 'generateAddressParameters'),
+  signMessage: _.partial(schemaValidate,
+    'signMessageParameters'),
+  verifyMessage: _.partial(schemaValidate,
+    'verifyMessageParameters'),
   signPaymentChannelClaim: _.partial(schemaValidate,
     'signPaymentChannelClaimParameters'),
   verifyPaymentChannelClaim: _.partial(schemaValidate,
diff --git a/src/offline/sign-message.js b/src/offline/sign-message.js
new file mode 100644
index 0000000000..2af5e2c58d
--- /dev/null
+++ b/src/offline/sign-message.js
@@ -0,0 +1,16 @@
+/* @flow */
+'use strict' // eslint-disable-line strict
+const common = require('../common')
+const keypairs = require('ripple-keypairs')
+const binary = require('ripple-binary-codec')
+const {validate, stringToUtf8ByteArray, bytesToHex} = common
+
+function signMessage(message: string,
+  privateKey: string
+): string {
+  validate.signMessage({message, privateKey})
+
+  return keypairs.sign(bytesToHex(stringToUtf8ByteArray(message)), privateKey)
+}
+
+module.exports = signMessage
diff --git a/src/offline/verify-message.js b/src/offline/verify-message.js
new file mode 100644
index 0000000000..53b9432764
--- /dev/null
+++ b/src/offline/verify-message.js
@@ -0,0 +1,16 @@
+/* @flow */
+'use strict' // eslint-disable-line strict
+const common = require('../common')
+const keypairs = require('ripple-keypairs')
+const binary = require('ripple-binary-codec')
+const {validate, stringToUtf8ByteArray, bytesToHex} = common
+
+function verifyMessage(message: string,
+  signature: string, publicKey: string
+): string {
+  validate.verifyMessage({message, signature, publicKey})
+
+  return keypairs.verify(bytesToHex(stringToUtf8ByteArray(message)), signature, publicKey)
+}
+
+module.exports = verifyMessage
diff --git a/test/api-test.js b/test/api-test.js
index 1a35f9970d..700632c0a0 100644
--- a/test/api-test.js
+++ b/test/api-test.js
@@ -452,6 +452,35 @@ describe('RippleAPI', function() {
     });
   });
 
+  it('signMessage', function() {
+    const privateKey =
+      'AC051121672EA8DC119D53AFBD0221607BE6B6B61A720BAB41C144B47E8782B3';
+    const result = this.api.signMessage(
+      requests.signMessage.message,
+      privateKey);
+    checkResult(responses.signMessage,
+      'signMessage', result)
+  });
+
+  it('verifyMessage', function() {
+    const publicKey =
+      '02DCAF8A5B6FBBC3582B87F326176C402B466EEE65FCC23189FC09F0834A78CE3C';
+    const result = this.api.verifyMessage(
+      requests.signMessage.message,
+      responses.signMessage, publicKey);
+    checkResult(true, 'verifyMessage', result)
+  });
+
+  it('verifyMessage - invalid', function() {
+    const publicKey =
+      '02BB1EE6437B0EA8D5DB68EF4FC7CA77F919764A11649ED49EE9C5A0950BA8BF04';
+    const result = this.api.verifyMessage(
+      requests.signMessage.message,
+      responses.signMessage, publicKey);
+    checkResult(false,
+      'verifyMessage', result)
+  });
+
   it('signPaymentChannelClaim', function() {
     const privateKey =
       'ACCD3309DB14D1A4FC9B1DAE608031F4408C85C73EE05E035B7DC8B25840107A';
diff --git a/test/fixtures/requests/index.js b/test/fixtures/requests/index.js
index ab5b67a69d..26e62dcb2e 100644
--- a/test/fixtures/requests/index.js
+++ b/test/fixtures/requests/index.js
@@ -61,6 +61,7 @@ module.exports = {
     escrow: require('./sign-escrow.json'),
     signAs: require('./sign-as')
   },
+  signMessage: require('./sign-message'),
   signPaymentChannelClaim: require('./sign-payment-channel-claim'),
   getPaths: {
     normal: require('./getpaths/normal'),
diff --git a/test/fixtures/requests/sign-message.json b/test/fixtures/requests/sign-message.json
new file mode 100644
index 0000000000..5df37aa1e2
--- /dev/null
+++ b/test/fixtures/requests/sign-message.json
@@ -0,0 +1,3 @@
+{
+  "message": "This is a test message for the signMessage and verifyMessage tests."
+}
diff --git a/test/fixtures/responses/index.js b/test/fixtures/responses/index.js
index fdf35151ba..e35243b54e 100644
--- a/test/fixtures/responses/index.js
+++ b/test/fixtures/responses/index.js
@@ -138,6 +138,7 @@ module.exports = {
     escrow: require('./sign-escrow.json'),
     signAs: require('./sign-as')
   },
+  signMessage: require('./sign-message'),
   signPaymentChannelClaim: require('./sign-payment-channel-claim'),
   combine: {
     single: require('./combine.json')
diff --git a/test/fixtures/responses/sign-message.json b/test/fixtures/responses/sign-message.json
new file mode 100644
index 0000000000..8f1bfd1dbc
--- /dev/null
+++ b/test/fixtures/responses/sign-message.json
@@ -0,0 +1 @@
+"3045022100E6D5B31AC54D3964DD016D5BC448CEF1D1643E7CB0190E6B289EBEAC8F92887802201A4EFD3B21C1792698D85770593B3503DD88C8BC513E19803F4AAA0951CEADB1"