MEDIATED CERTIFICATELESS CRYPTOSYSTEM FOR THE SECURITY OF DATA IN PUBLIC CLOUD

Nubila Jaleel, Chinju K

Abstract: Security is a serious issue in cloud computing. Encryption is the solution for the security in cloud. There are many encryption techniques. Each one has its own merits and demerits. In the case of identity based encryption it is free from security mediator, predefined keys are there, and have the problem of key escrow and certificate revocation. Then the arrival of mediated certificateless scheme eliminates the key escrow problem, and certificate revocation problem. In certificateless encryption scheme, key generation process is divided in between the user and the cloud. In our system data owner encrypt the data using its secret key. Then the data owner encrypt the secret key twice. Hence formed intermediate keys. Then send this encrypted data and intermediate keys to cloud. The cloud partially decrypt the intermediate key and send partially decrypted data and encrypted data to required user. The user decrypt the partialy decrypted data. Then the user will get the required key for decryption. so the user can decrypt it completly.The main advantage of our system is, the data owner can send same data to multiple clients with minimum cost.

Keywords: Cloud computing, Certificateless cryptography, Key escrow, Certificate revocation.

DOI: https://doi.org/10.15623/ijret.2015.0409021