def get_protected_url(self, key, **kwargs):                                                        
    connection = S3Connection(                                                                     
        AWS_ACCESS_KEY_ID,                                                          
        AWS_SECRET_ACCESS_KEY,                                                      
        is_secure=True,                                                                      
        calling_format='boto.s3.connection.OrdinaryCallingFormat',                           
        host='s3.eu-central-1.amazonaws.com',                                        
    )                                                                                        
    # Create a URL valid for 60 seconds.                                                     
    s3_url = connection.generate_url(                                                              
        60,                                                                                  
        'GET',                                                                               
        bucket='',  # Required                                                                          
        key=key,                                                              
    )                                                                                        
    return s3_url