Oracle Fusion Middleware Administration Guide for Oracle Directory Server Enterprise Edition

Attribute Encryption and Performance

While attribute encryption offers increased data security, it does impact system performance. Think carefully about which attributes require encryption, and encrypt only those attributes that you consider to be particularly sensitive.

Because sensitive data can be accessed directly through index files, the index keys that correspond to the encrypted attributes must be encrypted to ensure that the attributes are fully protected. Given that indexing already has an impact on Directory Server performance (without the added cost of encrypting index keys), configure attribute encryption before data is imported or added to the database for the first time. This procedure will ensure that encrypted attributes are indexed as such from the outset.