diff --git a/backend/.env.example b/backend/.env.example
index a07feb9..a93fdbd 100644
--- a/backend/.env.example
+++ b/backend/.env.example
@@ -32,5 +32,7 @@ REDIS_ENABLED=false
 REDIS_HOST=127.0.0.1
 REDIS_PORT=6379
 REDIS_PASSWORD=
+REDIS_DB=0
+
 
 
diff --git a/backend/app/Core/Cache.php b/backend/app/Core/Cache.php
index fec9b3b..595292d 100644
--- a/backend/app/Core/Cache.php
+++ b/backend/app/Core/Cache.php
@@ -35,6 +35,7 @@ class Cache
             $host = Env::get('REDIS_HOST', '127.0.0.1');
             $port = (int)Env::get('REDIS_PORT', 6379);
             $password = Env::get('REDIS_PASSWORD', null);
+            $db = (int)Env::get('REDIS_DB', 0);
 
             // Connect with 1.0s timeout to prevent request blocking
             $connected = $redis->connect($host, $port, 1.0);
@@ -43,10 +44,14 @@ class Cache
                 return null;
             }
 
-            if (!empty($password)) {
+            if ($password !== null && $password !== '' && strtolower($password) !== 'null') {
                 $redis->auth($password);
             }
 
+            if ($db > 0) {
+                $redis->select($db);
+            }
+
             self::$client = $redis;
         } catch (\Exception $e) {
             error_log('[Cache Error] Redis connection error: ' . $e->getMessage());
@@ -56,6 +61,14 @@ class Cache
         return self::$client;
     }
 
+    /**
+     * Helper to get prefixed key
+     */
+    private static function getPrefixedKey(string $key): string
+    {
+        return 'nabeh:' . $key;
+    }
+
     /**
      * Retrieve cache item by key.
      */
@@ -67,7 +80,8 @@ class Cache
         }
 
         try {
-            $value = $client->get($key);
+            $prefixedKey = self::getPrefixedKey($key);
+            $value = $client->get($prefixedKey);
             return $value !== false ? json_decode($value, true) : null;
         } catch (\Exception $e) {
             error_log('[Cache Error] Redis get failed: ' . $e->getMessage());
@@ -86,7 +100,8 @@ class Cache
         }
 
         try {
-            return $client->setex($key, $ttl, json_encode($value));
+            $prefixedKey = self::getPrefixedKey($key);
+            return $client->setex($prefixedKey, $ttl, json_encode($value));
         } catch (\Exception $e) {
             error_log('[Cache Error] Redis set failed: ' . $e->getMessage());
             return false;
@@ -104,7 +119,8 @@ class Cache
         }
 
         try {
-            return $client->del($key) > 0;
+            $prefixedKey = self::getPrefixedKey($key);
+            return $client->del($prefixedKey) > 0;
         } catch (\Exception $e) {
             error_log('[Cache Error] Redis delete failed: ' . $e->getMessage());
             return false;
diff --git a/backend/public/test_redis_cache.php b/backend/public/test_redis_cache.php
index b7fa64a..604c8fd 100644
--- a/backend/public/test_redis_cache.php
+++ b/backend/public/test_redis_cache.php
@@ -61,6 +61,23 @@ if (class_exists('\Redis')) {
             } else {
                 echo "   ❌ Failed to get correct value from Redis.\n";
             }
+
+            // Verify prefixing using a direct native Redis connection
+            $nativeRedis = new \Redis();
+            try {
+                if ($nativeRedis->connect(Env::get('REDIS_HOST', '127.0.0.1'), (int)Env::get('REDIS_PORT', 6379), 1.0)) {
+                    $nativeVal = $nativeRedis->get('nabeh:test_cache_key');
+                    if ($nativeVal) {
+                        echo "   ✅ Verified Prefixing: Native Redis key 'nabeh:test_cache_key' exists and has value: " . $nativeVal . "\n";
+                    } else {
+                        echo "   ❌ Prefixing test failed: key not found in native Redis.\n";
+                    }
+                    $nativeRedis->close();
+                }
+            } catch (\Exception $ex) {
+                echo "   ℹ️ Native verification connection skipped/failed: " . $ex->getMessage() . "\n";
+            }
+
             Cache::delete('test_cache_key');
         } else {
             echo "   ℹ️ Redis server is not running or unreachable (Fallback triggered, test completed successfully).\n";