1/17 Bluetooth Security Ain Shams University Faculty of Engineering Integrated Circuits Lab...
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Transcript of 1/17 Bluetooth Security Ain Shams University Faculty of Engineering Integrated Circuits Lab...
1/17
Bluetooth SecurityBluetooth Security
Ain Shams UniversityFaculty of Engineering
Integrated Circuits Lab
Presented byPresented by::
Mohammed Abdelsattar IsmailMohammed Abdelsattar IsmailSameh Talal Magd-El-DinSameh Talal Magd-El-DinSameh Assem IbrahimSameh Assem IbrahimAhmed Abdelhamid SalehAhmed Abdelhamid Saleh
2/17Bluetooth Security5-February-2001
-Overview-Overview -Blocks used -Weakness-Authentication -E1algorithm-Key handling -E3 -E2
-SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E0) -Timing -PRNG
EncryptionAuthentication
•Challenge-Response Scheme•SAFER+•Needed for encryption
•Optional•Symmetric Stream Cipher•Negotiable Key Size (8-128 bits)
3/17Bluetooth Security5-February-2001
E21E22E2
PIN or Random Number Random number
Kinit or Kmaster Kunit or KcombinationLink Keys
E0
E3
E1 Authentication
KcKcipher
Encryption
-Overview-Overview -Blocks used-Blocks used -Weakness-Authentication -E1algorithm-Key handling -E3 -E2
-SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E0) -Timing -PRNG
4/17Bluetooth Security5-February-2001
•PIN Number
•Initialization Key
•Unit Key
•User Tracking
-Overview-Overview -Blocks used -Weakness-Weakness-Authentication -E1algorithm-Key handling -E3 -E2
-SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E0) -Timing -PRNG
5/17Bluetooth Security5-February-2001
Challenge-Response Scheme:-Overview -Blocks used -Weakness-Authentication-Authentication -E1algorithm-Key handling -E3 -E2
-SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E0) -Timing -PRNG
6/17Bluetooth Security5-February-2001
The authentication function E1:-Overview -Blocks used -Weakness-Authentication-Authentication -E-E11algorithmalgorithm-Key handling -E3 -E2
-SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E0) -Timing -PRNG
7/17Bluetooth Security5-February-2001
E3-Key generation function for encryption:
-Overview -Blocks used -Weakness-Authentication -E1algorithm
-Key handling-Key handling -E-E33 -E2
-SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E0) -Timing -PRNG
8/17Bluetooth Security5-February-2001
E2-Key generation function for authentication:
1)E21 mode:
#Utilized when creating unit key and combination key.#It uses the function A’r .
It has two modes of operation:
2)E22 mode:
#Utilized when creating initialization key and master key.#It also uses the function A’r .
-Overview -Blocks used -Weakness-Authentication -E1algorithm
-Key handling-Key handling -E3
-E-E22
-SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E0) -Timing -PRNG
9/17Bluetooth Security5-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: Ar & Ar‘•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 -E1algorithm-Key handling -E3 -E2
-SAFER+-SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E0) -Timing -PRNG
10/17Bluetooth Security5-February-2001
ConfusionBit wise XOR – exponential – Addition mod 256Addition mod 256 – logarithmic – Bit wise XOR
e: (45i mod 257) mod 256l: I=e(j)
DiffusionPHT(x,y) = 2x+y mod 256, x+y mod 256)
Ar’PHT
PHT
PHT
PHT
PHT
PHT
PHT
+
e
@@
Declarations
log
@
e
+
e
+
log loge
@ + +
log
PHT
+ @
PHT
+@ @
PHT
+ @
PHT
round_input : (127:0)
e
@ + +
log log
Package List
ieee std_logic_1164 ieee std_logic_arith ieee std_logic_unsigned
e
@
e
@ +
log
+
log
PHT
+ @@
permute
PHT
+ + @@
PHT PHT PHT
PHT PHT PHT
PHT
PHT
PHT
permute
PHT
PHT
permute
PHT
e
@
+
PHT
round_output : (127:0)
PHT PHT PHT PHTPHT PHT
-Overview -Blocks used -Weakness-Authentication -E1algorithm-Key handling -E3 -E2
-SAFER+-SAFER+ -Round-Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E0) -Timing -PRNG
11/17Bluetooth Security5-February-2001
Bias wordsBp[I]=((45(4517p+I+1 mod 257)mod 257)mod 256)
-Overview -Blocks used -Weakness-Authentication -E1algorithm-Key handling -E3 -E2
-SAFER+-SAFER+ -Round -Key Schedule-Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E0) -Timing -PRNG
12/17Bluetooth Security5-February-2001
Encryption Round
KEY Scheduler
Controller
Register
-Overview -Blocks used -Weakness-Authentication -E1algorithm-Key handling -E3 -E2
-SAFER+-SAFER+ -Round -Key Schedule -Implementation-Implementation-Encryption -modes -Key Reduction -Engine (E0) -Timing -PRNG
13/17Bluetooth Security5-February-2001
-Overview -Blocks used -Weakness-Authentication -E1algorithm-Key handling -E3 -E2
-SAFER+ -Round -Key Schedule -Implementation-Encryption-Encryption -modes-modes -Key Reduction -Engine (E0) -Timing -PRNG
14/17Bluetooth Security5-February-2001
-Overview -Blocks used -Weakness-Authentication -E1algorithm-Key handling -E3 -E2
-SAFER+ -Round -Key Schedule -Implementation-Encryption-Encryption -modes -Key Reduction-Key Reduction -Engine (E0) -Timing -PRNG
15/17Bluetooth Security5-February-2001
-Overview -Blocks used -Weakness-Authentication -E1algorithm-Key handling -E3 -E2
-SAFER+ -Round -Key Schedule -Implementation-Encryption-Encryption -modes -Key Reduction -Engine (E-Engine (E00)) -Timing -PRNG
16/17Bluetooth Security5-February-2001
-Overview -Blocks used -Weakness-Authentication -E1algorithm-Key handling -E3 -E2
-SAFER+ -Round -Key Schedule -Implementation-Encryption-Encryption -modes -Key Reduction -Engine (E0)
-Timing-Timing -PRNG
17/17Bluetooth Security5-February-2001
Pseudo Random Number GeneratorPseudo Random Number Generator
Non Repeating
Randomly Generated
Bluetooth Standard•Software
•Hardware LFSR
•23 hr 18 min•3.2 kHz•28 bits•Serial
•128 bits•Parallel
-Overview -Blocks used -Weakness-Authentication -E1algorithm-Key handling -E3 -E2
-SAFER+ -Round -Key Schedule -Implementation-Encryption -modes -Key Reduction -Engine (E0) -Timing -PRNG-PRNG