RADIUS Attributes for the Delivery of Keying Material Joe Salowey Jesse Walker Tiebing Zhang Glen Zorn

Goals Securely transfer crypto keying material between RADIUS servers & client –Crypto-agility –NIST validation RADIUS as part of IEEE 802.1X & i systems Provide strong authentication for any RADIUS message –Crypto-agility –Accounting –Dynamic Authorization

Attributes Keying-Material –8-bit encryption type –16-bit application ID & key lifetime –128-bit KEK & Key IDs –Variable-length IV & keying material MAC-Randomizer –256-bit pseudo-random number –Substitute for Authenticator in CoA, etc. Message-Authentication-Code –Crypto-agile MAC

Rationale Extends existing RADIUS framework Attributes re-usable in various situations –Different keying methods IEEE i IEEE 802.1af WiMAX HOKEY (?) –Dynamic messages (e.g. CoA) –Accounting

Features No key management scheme specified –KEK, MAC Key “magically” provisioned –No reliance on particular derivation or provisioning methods –KEK-ID facilitates external key management schemes Application ID identifies key usage Crypto-agility supported –Encryption & MAC algorithms replaceable

Summary Provides crypto-agility for message authentication –Useful for CoA, accounting Provides crypto-agility for common key encryption attribute –Useful to carry MSK & other EAP-derived keys Efficient –Only necessary attributes encrypted

Next Steps Adopt as WG item –Draft in rev 12 Extensively reviewed Approach vetted by NIST –Multiple interoperable implementations Cisco 3eTI

Discussion?