Nishant Doshi

Nishant Doshi, Devesh Jinwala

Ciphertext policy attribute based encryption (CP-ABE) is a technique in which user with secret key containing attributes, only able to decrypt the message if the attributes in the policy match with the attributes in secret key. The existing methods that use reasonably computable decryption policies produce the ciphertext of size at least linearly varying with the number of attributes with additional pairing operations during encryption and decryption. In this paper, we propose a scheme in which ciphertext remains constant in length, irrespective of the number of attributes. Our scheme works for a threshold case: the number of attributes in a policy must be a subset of attributes in a secret key. The security of propose scheme is based on Decisional Bilinear Diffie-Hellman (DBDH) problem.

Nishant Doshi, Devesh Jinwala

In Ciphertext-Policy Attribute Based Encryption (CP-ABE), attributes are attached to the user's secret key and access policy is at-tached to the ciphertext. If attributes in the secret key of a user satisfy the policy then only the genuine user can decrypt the ciphertext. However, such scenario also necessitates periodic updating of the secret key with the changing attributes. According to our observations, the existing attempts at doing so are not efficient. In this paper, we propose a newer approach to add, update or delete the value of particular attribute effi-ciently without the knowledge of the other attributes.

Vishal Vadgama, Bhavin Tanti, Chirag Modi et al.

In today's world of E-Commerce everything comes online like Music, E-Books, Shopping all most everything is online. If you are using some service or buying things online then you have to pay for that. For that you have to do Net Banking or you have to use Credit card which will do online payment for you. In today's environment when everything is online, the service you are using for E-Payment must be secure and you must protect your banking information like debit card or credit card information from possible threat of hacking. There were lots way to threat like Key logger, Forgery Detection, Phishing, Shoulder surfing. Therefore, we reveal our actual information of Bank and Credit Card then there will be a chance to lose data and same credit card and hackers can use banking information for malicious purpose. In this paper we discuss available E-Payment protocols, examine its advantages and delimitation's and shows that there are steel needs to design a more secure E-Payment protocol. The suggested protocol is based on using hash function and using dynamic or virtual password, which protects your banking or credit card information from possible threat of hacking when doing online transactions.