Encrypted search with a public key

A method comprising:

• receiving, at data processing hardware, an operation request from a user device associated with a user, the operation request requesting encryption of data associated with the user and requesting that any unencrypted versions of the data after encryption be discarded, the data comprising a corpus of documents stored on a remote storage device in communication with the data processing hardware, wherein prior to receiving the operation request:
• receiving, at the data processing hardware, the corpus of documents uploaded by the user device;
• storing, by the data processing hardware, the corpus of documents on the remote storage device;
• and
• generating, by the data processing hardware, the search index for the corpus of documents stored on the remote storage device based on the keywords within the corpus of documents;
• receiving, at the data processing hardware, a public key associated with the user, the public key comprising an asymmetric cryptographic public key;
• generating, by the data processing hardware, a random data key, the data key comprising a symmetric cryptographic key;
• encrypting, by the data processing hardware, using the data key, a search index for the corpus of documents based on keywords within the corpus of documents;
• encrypting, by the data processing hardware, using the public key associated with the user, the data key;
• sending, by the data processing hardware, the encrypted data key to the user device associated with the user, the encrypted data key decryptable only with a private key associated with the public key, the private key comprising an asymmetric cryptographic private key inaccessible to the data processing hardware;
• and
• after sending the encrypted data key to the user, discarding, by the data processing hardware, the data key.