See pferraro's comments here: https://issues.jboss.org/browse/CLOUD-2417

"The shared secret used by AUTH is specified as an elytron credential reference, and the token can use any digest algorithm (not just MD5 and SHA-1).
e.g.
<protocol type="AUTH">
<digest-token algorithm="SHA-512"><!-- default is SHA-256 -->
<shared-secret-reference clear-text="bLogGimU"/><!-- or use a credential store -->
</digest-token>
</protocol>

Additionally, SYM_ENCRYPT should reference a elytron managed key store; the key entry password is specified as an elytron credential reference.
<protocol type="SYM_ENCRYPT" key-store="jgroups" key-alias="secret"><!-- references /subsystem=elytron/keystore=jgroups -->
<key-credential-reference clear-text="bLogGimU"/><!-- or use a credential store -->
<property name="encrypt_entire_message">true</property>
</protocol>
"