Secure File Storage On Cloud Using Hybrid Cryptography

Abstract

The servers that are accessed over the web and the software and databases that run on those servers are together known as "The Cloud". The amount of data needing storage is increasing every day and thus, there is a requirement for increased storage space. Cloud allows us to do the same. Storage of data on the cloud is done for various companies, colleges, for military purposes, etc. The data on the cloud is susceptible to various risks such as lack of backup services, data leakage, lack of control over your data being stored, etc. To provide a solution to these risks over cloud storage there are several ways, which include Cryptography and Steganography. Cryptography is quite popular for data security. The Cryptography technique translates original data into an unreadable form known as ciphertext. Text is converted into an unreadable form using keys. This ensures that only an authorized entity with the right key, can access the data from the cloud server. Ciphertext data is visible for everyone. There are two types of cryptography algorithms namely Symmetric Key cryptography and Asymmetric Key Cryptography. The use of a single cryptography algorithm provides basic security. In this paper, we have suggested the use of a combination of symmetric key cryptography algorithms namely: AES-GCM, Fernet, AES-CCM, CHACHA20_POLY1305 algorithm, which help to provide high-level security to the data. Here, the key is also secured using the Fernet algorithm. The file is split into N parts. Each part is encrypted simultaneously. For the file decryption purpose reverse process of encryption is applied.