![](bg7.png)
the period of validity t (time stamp) associated with
each file.
7 CONCLUSIONS
In this paper, we defined a new framework for data
security in cloud storage services. Through this
framework, we were able to achieve data
confidentiality and fine grained access control by
delegating key management and enforcement access
control to a TTP with minimal overhead on cloud
users .Our framework was also able to conquer two
of most important outsourced data sharing attacks:
replay attacks and collusion attacks. In addition, our
scheme was able to shift most of the extensive
computation load to the cloud. Our future work is to
evaluate this system and implement it in a real
application to prove its efficiency.
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