Disclosed embodiments relate to performing secure and flexible searches of encrypted data. Operations may include maintaining a database of a plurality of sets of encrypted data; receiving a transformed search query for the database, the transformed search query having undergone a transformation process at a client including: identifying a plaintext string in a search query at the client, applying the plaintext string to a language dictionary accessible to the client, receiving, based on the language dictionary, one or more plaintext search strings, and encrypting, at the client, the one or more plaintext search strings; and returning a result based on the transformed search query, the result being based on the encrypted one or more plaintext search strings.