• Pratiksha Mirgude
• Aarti Zagade
• Priti Chavan
• Harshada Gaikwad
• Mangal Kotkar

The intruders acquire the keys through backdoor, bribe, or coercion. Once the key is exposed, the only way to protect the data is by limiting access to the cipher text. The most common and strongest algorithms are already defined, the security lies into keys. Although the key is exposed we can still secure our data by dividing and distributing the cipher blocks on the multiple administrative domains so that it becomes very difficult for the intruder to gain access, assuming that intruder cannot compromise all the cipher blocks stored on the server. In the existing scheme, the data is stored on a single server so the attacker can easily get access to the user's confidential data by acquiring a key. In this paper, we propose a method i.e. dubbed Fortress method initially known as Bastion method which guarantees data security even if the key is Exposed, unless and until the attacker gets access to all the cipher blocks. Fortress method gives less than 5% overhead compared to existing secure encryption methods. We are additionally using the reverse circle cipher algorithm and ABE(attribute-based encryption) with outsourced decryption to increase efficiency and reduce decryption cost increased by ABE.

Key Exposure, ABE, Outsourced Decryption.

"Securing Cloud Data Using ABE Under Key Exposure For Outsourced Decryption", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 5, page no.357-359, May-2019, Available :http://www.jetir.org/papers/JETIR1905A60.pdf

"Securing Cloud Data Using ABE Under Key Exposure For Outsourced Decryption", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 5, page no. pp357-359, May-2019, Available at : http://www.jetir.org/papers/JETIR1905A60.pdf