Public Key Encryption With Keyword Search
The authors study the problem of searching on data that is encrypted using a public key system. Consider user Bob who sends email to user Alice encrypted under Alice's public key. An email gateway wants to test whether the email contains the keyword "Urgent" so that it could route the email accordingly. Alice, on the other hand does not wish to give the gateway the ability to decrypt all her messages. They define and construct a mechanism that enables Alice to provide a key to the gateway that enables the gateway to test whether the word "Urgent" is a keyword in the email without learning anything else about the email. They refer to this mechanism as Public Key Encryption with keyword Search.