+ message key material.
+
+o Cipher Name Length (2 bytes) - Indicates the length of the
+ Cipher Name field in the payload, not including any other
+ field.
+
+o Cipher Name (variable length) - Name of the cipher to use
+ in the private message encryption. If this field does not
+ exist then the default cipher of the SILC protocol is used.
+ See the [SILC1] for defined ciphers.