Bluetooth - Key risk-based approach Heirarchy.pptx

information security management system,' takes a whole-organization, risk-based approach to information security that addresses people, processes, and technology.

1. Higher Layer_KeyEst User Interaction (PIN) Pre- Config Pkey Init Key “K init ” Old Link Key Link Key Authentication Process Overlay Key Encryption Key Constraint Key Payload Key “KP” Encryption Process Shared Secret b/w 2x comm devices K init = E22( Pkey , IN_RAND, LPKey ) Short-lived key, used for pairing Shared secret, used after pairing K ovl = E22(K, RAND3, 16) Conveying the master key to each of the slave via Broadcast data Derived from Link key as: Kc =E3(K,EN_RAND,COF) Used for encryption in USA Impose restrictions on the export of encryption mech Conversion of 128 bits Kc into a Kc ’ (length < 128 bits) E 22 E 21 AC E E 3 Summary of Algorithms E 1 , E 3 , E 21 , E 22 use SAFER+ (Block Cipher) E is based on Stream Cipher 128 bits block cipher Key is directly input to E to generate a stream for Encryption Actual key used to Encrypt/ Decrypt B.T packets K p =E0(KC’, CK_VAL, BD_ADDR, EN_RAND) BLUETOOTH - KEY HIERARCHY OR . . . . g 1 L & g 2 L