diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index 7a6a938cbd8..965c6d3960b 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -508,6 +508,9 @@ Release 2.7.0 - UNRELEASED
     HADOOP-11355. When accessing data in HDFS and the key has been deleted,
     a Null Pointer Exception is shown. (Arun Suresh via wang)
 
+    HADOOP-11343. Overflow is not properly handled in caclulating final iv for
+    AES CTR. (Jerry Chen via wang)
+
 Release 2.6.0 - 2014-11-18
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/AesCtrCryptoCodec.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/AesCtrCryptoCodec.java
index 8f8bc661db7..5e286b9a60e 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/AesCtrCryptoCodec.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/AesCtrCryptoCodec.java
@@ -33,7 +33,6 @@ public abstract class AesCtrCryptoCodec extends CryptoCodec {
    * @see http://en.wikipedia.org/wiki/Advanced_Encryption_Standard
    */
   private static final int AES_BLOCK_SIZE = SUITE.getAlgorithmBlockSize();
-  private static final int CTR_OFFSET = 8;
 
   @Override
   public CipherSuite getCipherSuite() {
@@ -48,20 +47,18 @@ public abstract class AesCtrCryptoCodec extends CryptoCodec {
   public void calculateIV(byte[] initIV, long counter, byte[] IV) {
     Preconditions.checkArgument(initIV.length == AES_BLOCK_SIZE);
     Preconditions.checkArgument(IV.length == AES_BLOCK_SIZE);
-    
-    System.arraycopy(initIV, 0, IV, 0, CTR_OFFSET);
-    long l = 0;
-    for (int i = 0; i < 8; i++) {
-      l = ((l << 8) | (initIV[CTR_OFFSET + i] & 0xff));
+
+    int i = IV.length; // IV length
+    int j = 0; // counter bytes index
+    int sum = 0;
+    while (i-- > 0) {
+      // (sum >>> Byte.SIZE) is the carry for addition
+      sum = (initIV[i] & 0xff) + (sum >>> Byte.SIZE);
+      if (j++ < 8) { // Big-endian, and long is 8 bytes length
+        sum += (byte) counter & 0xff;
+        counter >>>= 8;
+      }
+      IV[i] = (byte) sum;
     }
-    l += counter;
-    IV[CTR_OFFSET + 0] = (byte) (l >>> 56);
-    IV[CTR_OFFSET + 1] = (byte) (l >>> 48);
-    IV[CTR_OFFSET + 2] = (byte) (l >>> 40);
-    IV[CTR_OFFSET + 3] = (byte) (l >>> 32);
-    IV[CTR_OFFSET + 4] = (byte) (l >>> 24);
-    IV[CTR_OFFSET + 5] = (byte) (l >>> 16);
-    IV[CTR_OFFSET + 6] = (byte) (l >>> 8);
-    IV[CTR_OFFSET + 7] = (byte) (l);
   }
 }
diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/TestCryptoCodec.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/TestCryptoCodec.java
index 79987cec37c..08231f98cbc 100644
--- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/TestCryptoCodec.java
+++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/TestCryptoCodec.java
@@ -23,7 +23,9 @@ import static org.junit.Assert.assertTrue;
 import java.io.BufferedInputStream;
 import java.io.DataInputStream;
 import java.io.IOException;
+import java.math.BigInteger;
 import java.security.GeneralSecurityException;
+import java.security.SecureRandom;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
@@ -41,6 +43,8 @@ import org.junit.Assert;
 import org.junit.Assume;
 import org.junit.Test;
 
+import com.google.common.primitives.Longs;
+
 public class TestCryptoCodec {
   private static final Log LOG= LogFactory.getLog(TestCryptoCodec.class);
   private static final byte[] key = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 
@@ -230,4 +234,64 @@ public class TestCryptoCodec {
     Assert.assertEquals(len, rand1.length);
     Assert.assertFalse(Arrays.equals(rand, rand1));
   }
+  
+  /**
+   * Regression test for IV calculation, see HADOOP-11343
+   */
+  @Test(timeout=120000)
+  public void testCalculateIV() throws Exception {
+    JceAesCtrCryptoCodec codec = new JceAesCtrCryptoCodec();
+    codec.setConf(conf);
+
+    SecureRandom sr = new SecureRandom();
+    byte[] initIV = new byte[16];
+    byte[] IV = new byte[16];
+
+    long iterations = 1000;
+    long counter = 10000;
+
+    // Overflow test, IV: 00 00 00 00 00 00 00 00 ff ff ff ff ff ff ff ff 
+    for(int i = 0; i < 8; i++) {
+      initIV[8 + i] = (byte)0xff;
+    }
+
+    for(long j = 0; j < counter; j++) {
+      assertIVCalculation(codec, initIV, j, IV);
+    }
+
+    // Random IV and counter sequence test
+    for(long i = 0; i < iterations; i++) {
+      sr.nextBytes(initIV);
+
+      for(long j = 0; j < counter; j++) {
+        assertIVCalculation(codec, initIV, j, IV);
+      }
+    }
+
+    // Random IV and random counter test
+    for(long i = 0; i < iterations; i++) {
+      sr.nextBytes(initIV);
+
+      for(long j = 0; j < counter; j++) {
+        long c = sr.nextLong();
+        assertIVCalculation(codec, initIV, c, IV);
+      }
+    }
+  }
+
+  private void assertIVCalculation(CryptoCodec codec, byte[] initIV,
+      long counter, byte[] IV) {
+    codec.calculateIV(initIV, counter, IV);
+
+    BigInteger iv = new BigInteger(1, IV);
+    BigInteger ref = calculateRef(initIV, counter);
+
+    assertTrue("Calculated IV don't match with the reference", iv.equals(ref));
+  }
+
+  private static BigInteger calculateRef(byte[] initIV, long counter) {
+    byte[] cb = Longs.toByteArray(counter);
+    BigInteger bi = new BigInteger(1, initIV);
+    return bi.add(new BigInteger(1, cb));
+  }
 }