Techniques of borrowing resources from external clouds to satisfy a user’s need paves way to several security threats. This is tackled by securing the data available in the borrowed resource. Data Security is provided using the traditional Advanced Encryption Standard (AES) algorithm. The traversal vulnerability issue poses a threat to security. This is handled in this work thereby, protecting every virtual machine (instance) created in the cloud from access by other malicious instances available in the same cloud. Security is evaluated based on cost. The results show that a secure cloud is designed. © Springer India 2015.