1/17 Bluetooth Security Ain Shams University Faculty of Engineering Integrated Circuits Lab Presented by: Mohammed Abdelsattar Ismail Sameh Talal Magd-El-Din Sameh Assem Ibrahim Ahmed Abdelhamid Saleh

Bluetooth Security 2/17 5-February Overview -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2 -SAFER+ -Round -Key Schedule -Implementation -Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG EncryptionAuthentication Challenge-Response Scheme SAFER+ Needed for encryption Optional Symmetric Stream Cipher Negotiable Key Size (8-128 bits)

Bluetooth Security 3/17 5-February-2001 E 21 E 22 E2E2 PIN or Random Number Random number K init or K master K unit or K combination Link Keys E0E0 E3E3 E1E1 Authentication KcKc K cipher Encryption -Overview -Blocks used -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2 -SAFER+ -Round -Key Schedule -Implementation -Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 4/17 5-February-2001 PIN Number Initialization Key Unit Key User Tracking -Overview -Blocks used -Weakness -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2 -SAFER+ -Round -Key Schedule -Implementation -Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 5/17 5-February-2001 Challenge-Response Scheme: -Overview -Blocks used -Weakness-Authentication -E 1 algorithm -Key handling -E 3 -E 2 -SAFER+ -Round -Key Schedule -Implementation -Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 6/17 5-February-2001 The authentication function E 1 : -Overview -Blocks used -Weakness-Authentication -E 1 algorithm -E 1 algorithm -Key handling -E 3 -E 2 -SAFER+ -Round -Key Schedule -Implementation -Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 7/17 5-February-2001 E 3 -Key generation function for encryption: -Overview -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 3 -E 2 -SAFER+ -Round -Key Schedule -Implementation -Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 8/17 5-February-2001 E 2 -Key generation function for authentication: 1)E 21 mode: # Utilized when creating unit key and combination key. #It uses the function A’ r. It has two modes of operation: 2)E 22 mode: # Utilized when creating initialization key and master key. #It also uses the function A’ r. -Overview -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2 -E 2 -SAFER+ -Round -Key Schedule -Implementation -Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 9/17 5-February-2001 Secure and Fast Encryption Routine SAFER K-64 (1993) - Cylink Corporation James L. Massay of ETH Zurich SAFER+ was submitted as one of the candidates to AES 1998 Block size = 128 bits, key size = 128, 192 or 256 bits Bluetooth: A r & A r ‘ 128 bits block, 128 bits key, 8 rounds, Encryption only Plaintext Block (16 bytes) Encryption Round 1 Encryption Round 8 Output Transformation Ciphertext Block (16 bytes) 2 16-Byte round subkeys 2 16-Byte round subkeys 1 16-Byte subkey -Overview -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2-SAFER+ -Round -Key Schedule -Implementation -Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 10/17 5-February-2001 Confusion Bit wise XOR – exponential – Addition mod 256 Addition mod 256 – logarithmic – Bit wise XOR e: (45 i mod 257) mod 256 l: I=e(j) Diffusion PHT(x,y) = 2x+y mod 256, x+y mod 256) Ar’Ar’ -Overview -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2-SAFER+ -Round -Round -Key Schedule -Implementation -Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 11/17 5-February-2001 Bias words B p [I]=((45 (45 17p+I+1 mod 257) mod 257)mod 256) -Overview -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2-SAFER+ -Round -Key Schedule -Key Schedule -Implementation -Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 12/17 5-February-2001 Encryption Round KEY Scheduler Controller Register -Overview -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2-SAFER+ -Round -Key Schedule -Implementation -Implementation -Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 13/17 5-February Overview -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2 -SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 14/17 5-February Overview -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2 -SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Key Reduction -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 15/17 5-February Overview -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2 -SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E 0 ) -Engine (E 0 ) -Timing -PRNG

Bluetooth Security 16/17 5-February Overview -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2 -SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -Timing -PRNG

Bluetooth Security 17/17 5-February-2001 Pseudo Random Number Generator Non Repeating Randomly Generated Bluetooth Standard Software HardwareLFSR 23 hr 18 min 3.2 kHz 28 bits Serial 128 bits Parallel -Overview -Blocks used -Weakness -Authentication -E 1 algorithm -Key handling -E 3 -E 2 -SAFER+ -Round -Key Schedule -Implementation -Encryption -modes -Key Reduction -Engine (E 0 ) -Timing -PRNG -PRNG