Methods For Encrypting Data, Decrypting Data, And Searching Encrypted Data

The invention provides computer-implemented methods for encrypting data, searching ciphertext, and decrypting ciphertext, and data processing apparatuses, computer programs, and computer readable storage media for achieving the same. Encrypting data comprises salting and then encrypting ciphertext, both processes using a respective exclusive OR operation. Decryption is achieved by the same process in reverse. Searching the ciphertext is achieved by generating a modifier and salted search term, before modifying the ciphertext with the modifier and performing a bytewise comparison between the salted search term and the modified ciphertext.