University of Brighton
The authors study the problem of searching on encrypted data, where the search is performed using a plaintext message or a keyword, rather than a message-specific trapdoor as done by state-of-the-art schemes. The use cases include delegation of keyword search e.g. to a cloud data storage provider or to an email server, using a plaintext message. They define a new cryptographic primitive called Plaintext-Checkable Encryption (PCE), which extends public-key encryption by the following functionality: given a plain-text, a ciphertext and a public key, it is universally possible to check whether the ciphertext encrypts the plaintext under the key.