4.2 Data Forward and Retrieval
One of the main challenges in cloud computing is forwarding the data to the authorized user and retrieving the data from the owner without any modification. These two challenges can be accomplished by using a QR (Quick response) code and Hash-Based Timestamp (HBT). The data owner directly checks the authorized user without any third parties.

4.2.1. Data Forward
Data can be forwarded to the authorized user by using QR code, which is a two-dimensional code and can be scanned by smart phones. There are several authentication mechanisms available such as static password, one time verification system, etc. Earlier, static password was used by cloud providers which caused lack of confidence in the data. In order to avoid this security issue, the owner has to change the password routinely. But it will be hard to remember every password often. In order to overcome this security issue, they use one time verification system. OTP provides more security because it generates a password for each and every login. OTP is generated for every session, which has only a short lifetime. Due to some network problems, OTP may get delay to reach the user which results in the expiry of OTP. These issues can be avoided by using QR code, which is more convenient to use. It is a multi-factor authentication for …show more content…
The lifetime of the QR code is unlimited. Hackers cannot hack the QR code. Hacking of QR code is a way in which it exploits the actions without modifying the QR code. This is impossible because two QR codes with different actions are not at all the same. QR code does not depend on any third parties. QR code-based authentication reduces load on cloud service provider because it does not need any key server to maintain the private and the public keys. QR code contains error correction mechanisms so that the data can be restored even when parts of the code gets