International Journal of Computer Applications (0975 – 8887) Volume 123 – No.11, August 2015 8 Digital Signature based Improved SECO Environment to Enhance Data Security in Cloud Computing Swaranjeet Kaur M.Tech Research scholar Sri Guru Granth Sahib World University Fatehgarh Sahib, Punjab Amritpal Kaur Assistant Professor Sri Guru Granth Sahib World University Fatehgarh Sahib, Punjab ABSTRACT Cloud computing itself is as a Service Model which means that everything is available on-demand over the internet. Every type of resources such as hardware and software resources can be accessed from anywhere by just connecting any network device to the internet. As it is based on internet services, security becomes major issue in this. Number of algorithms has been introduced to make secure user’s outsourced data on cloud. To solve this security issue, a secure and efficient data collaboration scheme SECO was introduced in cloud computing. This scheme resolves the security issue at a large extent but security needs to be enhanced more as security in itself is a vast area for research. In this paper, a Secure SECO Technique is proposed. The purpose of this technique is to enhance security by implementing digital signatures scheme in SECO scheme. This proposed technique helps to maximize the security of user’s outsourced data on cloud. General Terms Cloud Computing, Digital Signatures. Keywords Cloud Computing, SECO environment, Secure SECO environment, Certification Authority, Digital Certificates and Security Analysis. 1. INTRODUCTION There is numerous definition of Cloud Computing. According to U.S National Institute of Standards and Technology (NIST) ― Cloud Computing is a model for enabling convenient, on- demand network access to a shared pool of computing resources that can be rapidly provisioned and released with minimal management effort or cloud provider interaction [1].Cloud computing is made up of two words cloud or computing. The word cloud is used to represent the network whose internal setup is not known to you. For example, in network diagrams, the network of Internet Service Provider (ISP) is represented by cloud. Any simple internet or virtual private network (VPN), all networks are represented by cloud. The word computing means to calculate. Computing comprises data processing and calculations which are performed by using computers. This computing can be done on your local computer or on a centralized server or it can be done on both local and centralized server in distributed form according to your design. There can be one server or group of servers to provide network services. There can be different storage systems and database systems according to network size. Number of applications or services such as mail services can be deployed on these servers. That means, computing is done by client devices such as computers or laptops to use these applications or services and computing is done by network servers to provide these applications or services. Now by combining these two words, cloud or computing, it can be concluded that data related processing and calculation or computing is done on the cloud. It means this computing takes place on such a network about which there is no information known to you, i.e., number of servers providing services, configuration of these servers, where data is to be stored etc all these type of information is not available to you. It is the responsibility of cloud service provider. Cloud computing is pay-as-you-go model in which users are charged on the basis of usage. The basic requirement in cloud computing is network connection. It does not matter where you are, if internet connection is available then connect your network device such as mobile phone, laptop, tablet and desktop to the internet and enjoy the cloud services according to your demand. In other words, cloud computing can be defined as Computing as a Service where client computers or other devices access shared resources, software or information by connecting to the internet. The biggest advantage of outsourcing data to cloud is that user can access data whenever and wherever using any network device [2]. 1.1 Cloud Computing Services There are three types of services which are provided by cloud service provider. 1. Software as a Service (SaaS) in which software is provided over the internet and there is no need to install the software by the customers [3]. 2. Platform as a Service (PaaS) in which operating systems and middleware services are provided over the internet and customers can build their own applications [4]. 3. Infrastructure as a Service (IaaS) in which computational resources; storage systems and network systems are provided over the internet as a service [5]. This model is based on virtualization technology. 1.2 Five characteristics of cloud computing 1. Broad Network Access – It means you can access cloud services from anywhere in the world. 2. Rapid Elasticity – Cloud is scalable or elastic, i.e., whenever you need it, it is able to scale up or down as per your requirements. 3. Measured Service (pay as you go) – It means whatever amount you are using, it will be charging you only for that amount. 4. On-Demand Self Service – Cloud computing is available on demand so whenever you need it, it is immediately available to you within two or five minutes. 5. Resource Pooling – Number of resources are pooled in cloud computing for multiple consumers.