3.1.5.2 Encryption Types
KILE MUST<23> support the Advanced Encryption Standard (AES) encryption types:
AES256-CTS-HMAC-SHA1-96 [18] ([RFC3962] section 7)
AES128-CTS-HMAC-SHA1-96 [17] ([RFC3962] section 7)
and SHOULD<24> support the following encryption types, which are listed in order of relative strength:
All other Encryption Types SHOULD<25> be rejected. Kerberos V5 encryption type assigned numbers are specified in [RFC3961] section 8, [RFC4757] section 5, and [RFC3962] section 7.<26>