diff --git a/src/main/java/jota/IotaAPIProxy.java b/src/main/java/jota/IotaAPIProxy.java
index 818b10f..a017660 100644
--- a/src/main/java/jota/IotaAPIProxy.java
+++ b/src/main/java/jota/IotaAPIProxy.java
@@ -335,6 +335,8 @@ public class IotaAPIProxy {
         for (String trx : tailTxArray) {
 
             GetBundleResponse bundleResponse = getBundle(trx);
+            // TODO: review possibly dirty WA
+            if(bundleResponse == null) continue;
             Bundle gbr = new Bundle(bundleResponse.getTransactions(), bundleResponse.getTransactions().size());
             if (gbr != null && gbr.getTransactions() != null) {
                 if (inclusionStates) {
@@ -349,9 +351,9 @@ public class IotaAPIProxy {
 
         Collections.sort(finalBundles, new Comparator<Bundle>() {
             public int compare(Bundle c1, Bundle c2) {
-                if (Long.parseLong(c1.getTransactions().get(0).getTimestamp()) > Long.parseLong(c2.getTransactions().get(0).getTimestamp()))
-                    return -1;
                 if (Long.parseLong(c1.getTransactions().get(0).getTimestamp()) < Long.parseLong(c2.getTransactions().get(0).getTimestamp()))
+                    return -1;
+                if (Long.parseLong(c1.getTransactions().get(0).getTimestamp()) > Long.parseLong(c2.getTransactions().get(0).getTimestamp()))
                     return 1;
                 return 0;
             }
@@ -790,7 +792,7 @@ public class IotaAPIProxy {
             String address = signaturesToValidate.get(i).getAddress();
             boolean isValidSignature = Signing.validateSignatures(address, signatureFragments, bundleHash);
 
-            //if (!isValidSignature) throw new InvalidSignatureException();
+            if (!isValidSignature) throw new InvalidSignatureException();
         }
 
         return GetBundleResponse.create(bundle.getTransactions());
diff --git a/src/main/java/jota/model/Bundle.java b/src/main/java/jota/model/Bundle.java
index 457c108..9efd908 100644
--- a/src/main/java/jota/model/Bundle.java
+++ b/src/main/java/jota/model/Bundle.java
@@ -115,7 +115,7 @@ public class Bundle {
             long sum = 0;
             for (int j = 0; j < 27; j++) {
 
-                sum += (normalizedBundle[i * 27 + j] = Converter.value(Converter.trits("" + bundleHash.charAt(i * 27 + j))));
+                sum += (normalizedBundle[i * 27 + j] = Converter.value(Converter.tritsString("" + bundleHash.charAt(i * 27 + j))));
             }
 
             if (sum >= 0) {
diff --git a/src/main/java/jota/utils/Converter.java b/src/main/java/jota/utils/Converter.java
index 441c6ed..3329175 100644
--- a/src/main/java/jota/utils/Converter.java
+++ b/src/main/java/jota/utils/Converter.java
@@ -11,7 +11,7 @@ import java.util.LinkedList;
 import java.util.List;
 
 public class Converter {
-    
+
     private static final Logger log = LoggerFactory.getLogger(Converter.class);
 
     private static final int RADIX = 3;
@@ -91,6 +91,13 @@ public class Converter {
 
         return convertToIntArray(tritsList);
     }
+    public static int[] tritsString(final String trytes){
+        int[] d = new int[3 * trytes.length()];
+        for (int i = 0; i < trytes.length(); i++) {
+            System.arraycopy(TRYTE_TO_TRITS_MAPPINGS[Constants.TRYTE_ALPHABET.indexOf(trytes.charAt(i))], 0, d, i * NUMBER_OF_TRITS_IN_A_TRYTE, NUMBER_OF_TRITS_IN_A_TRYTE);
+        }
+        return d;
+    }
 
     public static int[] trits(final String trytes) {
         final List<Integer> trits = new LinkedList<>();
@@ -238,14 +245,14 @@ public class Converter {
                 + trx.getBranchTransaction()
                 + trx.getNonce();
     }
-    
+
     public static Transaction transactionObject(final String trytes) {
-        
+
         if (StringUtils.isEmpty(trytes)) {
             log.warn("Warning: empty trytes in input for transactionObject");
             return null;
         }
-        
+
         // validity check
         for (int i = 2279; i < 2295; i++) {
             if (trytes.charAt(i) != '9') {
@@ -253,7 +260,7 @@ public class Converter {
                 return null;
             }
         }
-        
+
         int[] transactionTrits = Converter.trits(trytes);
         int[] hash = new int[243];
 
diff --git a/src/main/java/jota/utils/Signing.java b/src/main/java/jota/utils/Signing.java
index 2d27b42..c6110fd 100644
--- a/src/main/java/jota/utils/Signing.java
+++ b/src/main/java/jota/utils/Signing.java
@@ -163,7 +163,7 @@ public class Signing {
                 digests[i * 243 + j] = digestBuffer[j];
             }
         }
-        System.out.println(Arrays.toString(digests).replaceAll("\\s+",""));
+        //System.out.println(Arrays.toString(digests).replaceAll("\\s+",""));
         String address = Converter.trytes(address(digests));
 
         return (expectedAddress.equals(address));