Cumulus4j is an encryption plug-in for DataNucleus. Applications can thus use JDO or JPA to persist their data into every common database. Using the Bouncy Castle cryptography libs, it provides strong encryption via AES, TwoFish or other algorithms.
XTEA (eXtended Tiny Encryption Algorithm) support for db4o open source object database. XTEA is a block cipher that operates on a 64-bit block size with a 128-bit key. An extremely tiny but very fast encryption algorithm (with cycles less than 32 rounds)