diff -r 000000000000 -r 6474c204b198 mobile/android/tests/background/junit3/src/fxa/TestBrowserIDKeyPairGeneration.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/tests/background/junit3/src/fxa/TestBrowserIDKeyPairGeneration.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,49 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+package org.mozilla.gecko.background.fxa;
+
+import java.security.GeneralSecurityException;
+
+import org.mozilla.gecko.background.helpers.AndroidSyncTestCase;
+import org.mozilla.gecko.browserid.BrowserIDKeyPair;
+import org.mozilla.gecko.browserid.DSACryptoImplementation;
+import org.mozilla.gecko.browserid.JSONWebTokenUtils;
+import org.mozilla.gecko.browserid.RSACryptoImplementation;
+import org.mozilla.gecko.browserid.SigningPrivateKey;
+import org.mozilla.gecko.browserid.VerifyingPublicKey;
+import org.mozilla.gecko.sync.ExtendedJSONObject;
+import org.mozilla.gecko.sync.Utils;
+
+public class TestBrowserIDKeyPairGeneration extends AndroidSyncTestCase {
+  public void doTestEncodeDecode(BrowserIDKeyPair keyPair) throws Exception {
+    SigningPrivateKey privateKey = keyPair.getPrivate();
+    VerifyingPublicKey publicKey = keyPair.getPublic();
+
+    ExtendedJSONObject o = new ExtendedJSONObject();
+    o.put("key", Utils.generateGuid());
+
+    String token = JSONWebTokenUtils.encode(o.toJSONString(), privateKey);
+    assertNotNull(token);
+
+    String payload = JSONWebTokenUtils.decode(token, publicKey);
+    assertEquals(o.toJSONString(), payload);
+
+    try {
+      JSONWebTokenUtils.decode(token + "x", publicKey);
+      fail("Expected exception.");
+    } catch (GeneralSecurityException e) {
+      // Do nothing.
+    }
+  }
+
+  public void testEncodeDecodeSuccessRSA() throws Exception {
+    doTestEncodeDecode(RSACryptoImplementation.generateKeyPair(1024));
+    doTestEncodeDecode(RSACryptoImplementation.generateKeyPair(2048));
+  }
+
+  public void testEncodeDecodeSuccessDSA() throws Exception {
+    doTestEncodeDecode(DSACryptoImplementation.generateKeyPair(512));
+    doTestEncodeDecode(DSACryptoImplementation.generateKeyPair(1024));
+  }
+}