Preserving the data type of an encrypted data element

摘要

A method and a system for data type preserving encryption of a data element in a relational database, wherein each data element comprises a string of at least one character. The method comprises the steps of: reading the type of a data element which is to be encrypted; and interpreting said data type in order to form a restricting character set for each character of said data element. Then encryption using said encryption means for encrypting each character of said data element into an encrypted character using said restricted character set to control said encryption means to only create encrypted characters included said restricting character set is performed.