• Cryptix is compatible with JDK 1.1, 1.2, and 1.3.
• BouncyCastle provides a JCE 1.2.1 implementation compatible with JDK 1.1, 1.2, and 1.3. They also have a version suitable for JDK 1.4 and the SUN JCE.

For systems with high security needs, use a product that provides security toolkits bundled with both JCE and XML Signature implementations:

• Certicom's Trustpoint/Java
• RSA's BSAFE Crypto-J
• Entrust's Entrust Authority