Hazelcast offers features which allow to reach a required privacy on communication level by enabling encryption. Encryption is based on Java Cryptography Architecture (JCA).

There are two different encryption features:

  1. TLS protocol

    • transport level encryption

    • supported by members and clients

    • TCP-only, i.e., multicast join messages are not encrypted

      More details in the TLS/SSL section

  2. Symmetric encryption for Hazelcast member protocol

    • only supported by the members; communication with clients is not encrypted

    • multicast join messages are encrypted, too

The preferred and recommended feature is the TLS protocol as it’s a standard way how to protect communication on transport level: Both TLS and symmetric encryption are for encrypting the network traffic. TLS is already superior to symmetric encryption on more than one aspects as seen above. Symmetric encryption is only supported in member-member communication while TLS can encrypt client communications as well. When there is no specific reason to use symmetric encryption, we recommend you to use the TLS protocol.

Symmetric encryption for Hazelcast member protocol can be configured with cipher algorithms implemented by security providers and accessed through Java Cryptography Architecture. Check documentation of your Java version to learn about supported algorithm names. The following are some examples:

  • AES

  • PBEWithMD5AndDES

  • DES/ECB/PKCS5Padding

  • Blowfish

Hazelcast uses MD5 message-digest algorithm as the cryptographic hash function. You can also use the salting process by giving a salt and password which are then concatenated and processed with MD5, and the resulting output is stored with the salt.

In symmetric encryption, each member uses the same key, so the key is shared. Here is an example configuration for symmetric encryption.

  • XML

  • YAML

        <symmetric-encryption enabled="true">
      enabled: true
      algorithm: AES
      salt: thesalt
      password: thepass
      iteration-count: 175

You set the encryption algorithm, the salt, password and the iteration count to be used for generating the secret key. You also need to set the enabled attribute to true. Note that all members should have the same encryption configuration.

Since symmetric encryption relies on JCA, you can additionally benefit from the algorithms provided by the Bouncy Castle Crypto APIs. For this, you need to set the hazelcast.security.bouncy.enabled property to true.