A database access system may protect a field by storing the field as one or more underlying fields within a database. The database engine may not have access to keys used to protect the underlying fields within the database, such as by encryption, while the database access system may have access to the keys. Underlying fields may be used to store protected data and aid in the querying of protected data. The database access system may modify queries to use the underlying fields, which may include encrypting query terms and/or modifying query terms to fit the use of the underlying fields. The database access system may modify query results to match the format of the original query, which may include decrypting protected results and/or removing underlying fields.