Public cloud user authentication and data confidentiality using image steganography with hash function

Public cloud is an environment in which many users share resources, but the consumer has to sacrifice security owing to the multi tenancy feature of cloud computing. However, maintaining Confidentiality and Security for critical data is highly challenging. Taking account of the static nature of user validation, this paper address authentication and confidentiality issues. A methodology has been proposed for user authentication to make cloud server, dynamic in nature, based on the time stamp and other parameters. The confidential data are embedded randomly in images using steganography as a basic technique, in which a new method of encryption and decryption is proposed. The methodology of encryption or decryption uses odd Fibonacci series values and a hash function to prepare hash value series. This hash value series is multiplied with ASCII codes of the original data which need to embed, in decryption process and similar technique have been used here, rather than the technique of multiplying ASCII codes with hash value using division operation.