diff --git a/commons/src/main/java/org/eclipse/kapua/commons/model/id/IdGenerator.java b/commons/src/main/java/org/eclipse/kapua/commons/model/id/IdGenerator.java
index feda5687e76..e178e8cb6f4 100644
--- a/commons/src/main/java/org/eclipse/kapua/commons/model/id/IdGenerator.java
+++ b/commons/src/main/java/org/eclipse/kapua/commons/model/id/IdGenerator.java
@@ -38,9 +38,7 @@ private IdGenerator() {
      * @return
      */
     public static BigInteger generate() {
-        byte[] bytes = new byte[ID_SIZE];
-        SECURE_RANDOM.nextBytes(bytes);
-        return new BigInteger(bytes);
+        return new BigInteger(ID_SIZE, SECURE_RANDOM);
     }
 
 }
diff --git a/commons/src/main/java/org/eclipse/kapua/commons/setting/system/SystemSettingKey.java b/commons/src/main/java/org/eclipse/kapua/commons/setting/system/SystemSettingKey.java
index cbdeff2286b..519d8343b19 100644
--- a/commons/src/main/java/org/eclipse/kapua/commons/setting/system/SystemSettingKey.java
+++ b/commons/src/main/java/org/eclipse/kapua/commons/setting/system/SystemSettingKey.java
@@ -167,7 +167,7 @@ public enum SystemSettingKey implements SettingKey {
     OSGI_CONTEXT("commons.osgi.context"),
 
     /**
-     * Set the Kapua key size
+     * Set the Kapua key size (the size is expressed in bits)
      */
     KAPUA_KEY_SIZE("commons.entity.key.size"),
 
diff --git a/commons/src/main/resources/kapua-environment-setting.properties b/commons/src/main/resources/kapua-environment-setting.properties
index 75674b693a6..19c3dfe20af 100644
--- a/commons/src/main/resources/kapua-environment-setting.properties
+++ b/commons/src/main/resources/kapua-environment-setting.properties
@@ -58,5 +58,6 @@ commons.osgi.context=false
 # 
 # Entity settings
 # 
-commons.entity.key.size=8
+#set the generated ids size (in bits) (please don't use key size greater than 63 with H2 since H2 maps the biginteger to a long. see http://www.h2database.com/html/datatypes.html#bigint_type)
+commons.entity.key.size=63
 commons.entity.insert.max.retry=3
\ No newline at end of file
diff --git a/commons/src/test/java/org/eclipse/kapua/commons/model/KapuaIdGeneratorTest.java b/commons/src/test/java/org/eclipse/kapua/commons/model/KapuaIdGeneratorTest.java
index 0ec86d719ff..9eb209a03c9 100644
--- a/commons/src/test/java/org/eclipse/kapua/commons/model/KapuaIdGeneratorTest.java
+++ b/commons/src/test/java/org/eclipse/kapua/commons/model/KapuaIdGeneratorTest.java
@@ -13,11 +13,13 @@
 package org.eclipse.kapua.commons.model;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.fail;
 
 import java.math.BigInteger;
 
 import org.eclipse.kapua.KapuaException;
+import org.eclipse.kapua.commons.model.id.IdGenerator;
 import org.eclipse.kapua.commons.model.misc.CollisionEntity;
 import org.eclipse.kapua.commons.model.misc.CollisionIdGenerator;
 import org.eclipse.kapua.commons.model.misc.CollisionServiceImpl;
@@ -109,4 +111,19 @@ public void testKeyNoKeyCollision() {
                     collisionIdGenerator.getGeneretedValuesCount());
         }
     }
+
+    @Test
+    /**
+     * Just generate few ids and check if the numbers are fitted into the expected limits
+     * 
+     * @throws Exception
+     */
+    public void testIdGeneratorBound() throws Exception {
+        int idSize = SystemSetting.getInstance().getInt(SystemSettingKey.KAPUA_KEY_SIZE);
+        BigInteger upperLimit = BigInteger.valueOf(2).pow(idSize);
+        for (int i = 0; i < 1000; i++) {
+            BigInteger generated = IdGenerator.generate();
+            assertFalse("The generated id is out of the expected bounds!", generated.compareTo(BigInteger.ZERO) < 0 || generated.compareTo(upperLimit) != -1);
+        }
+    }
 }
diff --git a/commons/src/test/resources/kapua-environment-setting.properties b/commons/src/test/resources/kapua-environment-setting.properties
index a02f2417422..cb3af26332a 100644
--- a/commons/src/test/resources/kapua-environment-setting.properties
+++ b/commons/src/test/resources/kapua-environment-setting.properties
@@ -59,5 +59,6 @@ commons.osgi.context=false
 # 
 # Entity settings
 # 
-commons.entity.key.size=8
+#set the generated ids size (in bits) (please don't use key size greater than 63 with H2 since H2 maps the biginteger to a long. see http://www.h2database.com/html/datatypes.html#bigint_type)
+commons.entity.key.size=63
 commons.entity.insert.max.retry=3
\ No newline at end of file
diff --git a/service/account/internal/src/test/resources/kapua-environment-setting.properties b/service/account/internal/src/test/resources/kapua-environment-setting.properties
index 36197419da3..2ce364b2809 100644
--- a/service/account/internal/src/test/resources/kapua-environment-setting.properties
+++ b/service/account/internal/src/test/resources/kapua-environment-setting.properties
@@ -55,15 +55,10 @@ broker.port=1884
 #
 # Entity settings
 #
-commons.entity.key.size=8
+#set the generated ids size (in bits) (please don't use key size greater than 63 with H2 since H2 maps the biginteger to a long. see http://www.h2database.com/html/datatypes.html#bigint_type)
+commons.entity.key.size=63
 commons.entity.insert.max.retry=3
 
 character.encoding=UTF-8
 
 commons.osgi.context=false
-
-# 
-# Entity settings
-# 
-commons.entity.key.size=8
-commons.entity.insert.max.retry=3
\ No newline at end of file
diff --git a/service/datastore/internal/src/test/resources/kapua-environment-setting.properties b/service/datastore/internal/src/test/resources/kapua-environment-setting.properties
index c1d7ccf4271..73a68eb4beb 100644
--- a/service/datastore/internal/src/test/resources/kapua-environment-setting.properties
+++ b/service/datastore/internal/src/test/resources/kapua-environment-setting.properties
@@ -58,5 +58,6 @@ commons.osgi.context=false
 # 
 # Entity settings
 # 
-commons.entity.key.size=8
+#set the generated ids size (in bits) (please don't use key size greater than 63 with H2 since H2 maps the biginteger to a long. see http://www.h2database.com/html/datatypes.html#bigint_type)
+commons.entity.key.size=63
 commons.entity.insert.max.retry=3
\ No newline at end of file
diff --git a/service/device/registry/internal/src/test/resources/kapua-environment-setting.properties b/service/device/registry/internal/src/test/resources/kapua-environment-setting.properties
index a02f2417422..cb3af26332a 100644
--- a/service/device/registry/internal/src/test/resources/kapua-environment-setting.properties
+++ b/service/device/registry/internal/src/test/resources/kapua-environment-setting.properties
@@ -59,5 +59,6 @@ commons.osgi.context=false
 # 
 # Entity settings
 # 
-commons.entity.key.size=8
+#set the generated ids size (in bits) (please don't use key size greater than 63 with H2 since H2 maps the biginteger to a long. see http://www.h2database.com/html/datatypes.html#bigint_type)
+commons.entity.key.size=63
 commons.entity.insert.max.retry=3
\ No newline at end of file
diff --git a/service/security/shiro/src/test/resources/kapua-environment-setting.properties b/service/security/shiro/src/test/resources/kapua-environment-setting.properties
index 2d271ad16f0..2b2e0df0808 100644
--- a/service/security/shiro/src/test/resources/kapua-environment-setting.properties
+++ b/service/security/shiro/src/test/resources/kapua-environment-setting.properties
@@ -60,5 +60,6 @@ commons.osgi.context=false
 # 
 # Entity settings
 # 
-commons.entity.key.size=8
+#set the generated ids size (in bits) (please don't use key size greater than 63 with H2 since H2 maps the biginteger to a long. see http://www.h2database.com/html/datatypes.html#bigint_type)
+commons.entity.key.size=63
 commons.entity.insert.max.retry=3
\ No newline at end of file
diff --git a/service/user/internal/src/test/resources/kapua-environment-setting.properties b/service/user/internal/src/test/resources/kapua-environment-setting.properties
index a02f2417422..cb3af26332a 100644
--- a/service/user/internal/src/test/resources/kapua-environment-setting.properties
+++ b/service/user/internal/src/test/resources/kapua-environment-setting.properties
@@ -59,5 +59,6 @@ commons.osgi.context=false
 # 
 # Entity settings
 # 
-commons.entity.key.size=8
+#set the generated ids size (in bits) (please don't use key size greater than 63 with H2 since H2 maps the biginteger to a long. see http://www.h2database.com/html/datatypes.html#bigint_type)
+commons.entity.key.size=63
 commons.entity.insert.max.retry=3
\ No newline at end of file