diff --git a/src/test/java/org/apache/sling/auth/form/impl/TokenStoreTest.java b/src/test/java/org/apache/sling/auth/form/impl/TokenStoreTest.java
new file mode 100644
index 0000000..89526d4
--- /dev/null
+++ b/src/test/java/org/apache/sling/auth/form/impl/TokenStoreTest.java
@@ -0,0 +1,122 @@
+package org.apache.sling.auth.form.impl;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+import java.math.BigInteger;
+import java.util.UUID;
+
+import org.junit.Before;
+import org.junit.Test;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/* TokenStore tests, incomplete for now */
+ public class TokenStoreTest {
+    private TokenStore store;
+    private static final long sessionTimeoutMsec = 60 * 1000L;
+    private static final long defaultExpirationTimeMsec = System.currentTimeMillis() + sessionTimeoutMsec / 2;
+    private static final boolean defaultFastSeed = false;
+    private static final String userId = "user_" + UUID.randomUUID();
+    private String encodedToken;
+    private File tokenFile;
+    private int additionalFileIndex;
+    
+    private File additionalTokenFile() {
+        return new File(tokenFile.getParent(), tokenFile.getName() + "-" + additionalFileIndex++);
+    }
+
+    @Before
+    public void setup() throws Exception {
+        tokenFile = File.createTempFile(getClass().getName(), "tokenstore");
+        store = new TokenStore(tokenFile, sessionTimeoutMsec, defaultFastSeed);
+        encodedToken = store.encode(defaultExpirationTimeMsec, userId);
+    }
+
+    @Test
+    public void validTokenTest() throws Exception {
+        assertTrue(store.isValid(encodedToken));
+    }
+
+    @Test
+    public void invalidTokensTest() throws Exception {
+        final String [] invalid = {
+            "1@21@3",
+            "nothing",
+            "0@bad@token"
+        };
+        for(String token : invalid) {
+            assertFalse(store.isValid(token));
+        }        
+    }
+
+    @Test
+    public void expiredTokenTest() throws Exception {
+        final String expired = store.encode(1, userId);
+        Thread.sleep(50);
+        assertFalse(store.isValid(expired));
+    }
+
+    @Test
+    public void loadTokenFileTest() throws Exception {
+        final TokenStore newStore = new TokenStore(tokenFile, sessionTimeoutMsec, defaultFastSeed);
+        assertTrue(newStore.isValid(encodedToken));
+
+        final TokenStore emptyStore = new TokenStore(additionalTokenFile(), sessionTimeoutMsec, defaultFastSeed);
+        assertFalse(emptyStore.isValid(encodedToken));
+    }
+
+    @Test
+    public void encodingPartsTest() throws Exception {
+
+        // Test with both a normal and "fast seed" store
+        final TokenStore [] testStores = {
+            new TokenStore(additionalTokenFile(), sessionTimeoutMsec, true),
+            new TokenStore(additionalTokenFile(), sessionTimeoutMsec, false)
+        };
+
+        for(TokenStore testStore : testStores) {
+            String lastHexNumber = "";
+            for(int i=1 ; i < 100; i++) {
+                final String uniqueUserId = "user-" + i;
+                final String [] parts = TokenStore.split(testStore.encode(123, uniqueUserId));
+    
+                // First a unique large hex number
+                assertFalse(parts[0].equals(lastHexNumber));
+                lastHexNumber = parts[0];
+                new BigInteger(lastHexNumber, 16);
+                assertTrue(lastHexNumber.length() > 20);
+    
+                // Then the timeout prefixed by something else
+                assertEquals("123", parts[1].substring(1));
+    
+                // Then the user id
+                assertEquals(uniqueUserId, parts[2]);
+            }
+        }
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void nullTokenFileTest() throws Exception {
+        new TokenStore(null, sessionTimeoutMsec, defaultFastSeed);
+    }
+}