Open Access

Sayan Saha

• Encryption techniques allow storing and transferring of sensitive information securely by using encryption at rest and encryption in transit, respectively. However, when computation is performed on these sensitive data, the data needs to be decrypted first and encrypted again after performing the computations. During the computations, the sensitive data becomes vulnerable to attackers as it's inEncryption techniques allow storing and transferring of sensitive information securely by using encryption at rest and encryption in transit, respectively. However, when computation is performed on these sensitive data, the data needs to be decrypted first and encrypted again after performing the computations. During the computations, the sensitive data becomes vulnerable to attackers as it's in decrypted form. Homomorphic encryption, a special type of encryption technique that allows computation on encrypted data can be used to solve the above-mentioned problem. The best way to achieve maximum security with homomorphic encryption is to perform at least the homomorphic encryption and decryption on the client side (browser) of a web application by not trusting the server. At present time there are many libraries with different homomorphic schemes available for homomorphic encryption. However, there are very few to no JavaScript libraries available to perform homomorphic encryption on the client side of any web application. This thesis mainly focuses on the JavaScript implementation of client-side homomorphic encryption. The fully homomorphic encryption scheme BFV is selected for the implementation. After implementing the fully homomorphic encryption scheme based on the “py-fhe” library, tests are also carried out in order to determine the applicability (in terms of time consumption, security and correctness) of this implementation in a web application by comparing the performance and security for different test cases and different settings.…