Cloud computing is the next stage in evolution of the internet, which provides large amounts of computing andstorage to customers provisioned as a service over the internet. However, cloud computing faces so manysecurity challenges due to the possible compromise or byzantine failures. In this paper, we focus on Ensuringdata storage security in cloud computing, which is an important aspect of Quality of Service (QoS). We proposean effective and flexible distribution verification protocol to address data storage security in cloud computing.In this protocol, we rely on erasure code for the availability, reliability of data and utilize tokenprecomputation using Sobol Sequence to verify the integrity of erasure coded data rather than PseudorandomData in existing systems. Unlike prior works, our scheme provides more security to user data stored in cloudcomputing. The performance analysis shows that our scheme is more secure than existing systems againstByzantine failure, unauthorized data modification attacks, and even cloud server colluding attacks.