mini-project 2006 secure positioning in vehicular networks based on map sharing with radars...
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Mini-Project 2006
Secure positioning in vehicular networks based on
map sharing with radarsMini-Project
IC-29 Self-Organized Wireless and Sensor Networks
Csaba Árendás
Tutors: Maxim Raya Prof. Jean-Pierre Hubaux
Mini-Project 2006 2
Motivation
• Positioning– Positioning without need for strong
evidence– Navigation systems– GPS, GSM
• Secure positioning– To be sure that the position is correct– Military applications (smart bombs)
• Secure positioning in vehicular network– Collision warning– Life critical application
Mini-Project 2006 3
Problem statement – secure positioning in vehicular
networksG
PS sig
nal
[You
r pos
ition
is 1]
A
B`s map:A is at 55B is at 2
DS
RC
broadcast
signal
SignedB
yA [I am
A,
my position is 55] B
GPS signal
[Your position is 2]
GPS position 1 GPS position 2
Mini-Project 2006 4
Solution overview
• Precise distance measurement– ACC radars, relative positions
• Position authentication– Position keys
• ID authentication– Conventional cryptography– Public key cryptography
• Communication– Radar communication– DSRC broadcast radio communication
Mini-Project 2006 5
System model, assumptions
• Precise ACC radars– Precise distance measurement,– Radar communication– Vehicle's 360 degrees area is covered
• Broadcast radio communication device• TPD for each vehicle
– Contains Certificate, ID, public, private keys– Issued by CA at the police station– Given with the number plate registration– Hash, sign, verify a message, RND generation
Mini-Project 2006 6
State of the art Adaptive cruise control systems
Zone 8Zone 7Z
one
2
Zon
e 6
Zone 5
Zone 3Zone 4
1
Zone 7
Zon
e 2
Zon
e 6
Zone 5
Zone 3 Zone 4
A
B
Top left point
T
op right point
2 3
Shortest point
Mini-Project 2006 7
Zone 8Zone 7
Zon
e 2
Zone 1Z
one
6
Zone 4
Zone 8Zone 7
Zone 1Z
one
6
Zone 5
Zone 3Zone 4
Zone 8
Zon
e 2
Zone 1
Zone 5
Zone 3Zone 4
distance = PositionKey[1] A<->B
A
B
C
distance = PosK
ey[2] B<->C
Distance = PositionKey[3] A<->C
Generation of the position key - ideal case
Mini-Project 2006 8
Generation of the position key - real case
• Since the other vehicle front side figure (or other side) is not a standard the distance measurements might differ from each other
• The key length in this way is limited by the maximal distance measurement difference
]BA[dis Vehicle A Vehicle B
RADAR
RADAR
Distance measurement A->B (radar)
Distance measurement B->A (radar)
]AB[dis
)YX(cesin,C]AB[disC]BA[dis BA
AC
BC
X
Y
Mini-Project 2006 9
Generation of the position key - final solution
1t]BA[dis
Vehicle A Vehicle B
RADAR
RADAR
1t]AB[dis
yPositionKe]BA[dis]BA[dis21t t
2t]BA[dis
2t]AB[dis
Vehicle A
RADAR
Vehicle B
RADAR
1t
2t
21t t]AB[dis]AB[disyPositionKe
A’s clo
sest
point for B
B’s closest point for A
Mini-Project 2006 10
Zon
e 6
Zone 5
Zone 7
Zon
e 2
Zon
e 6
Zone 5
Zone 3 Zone 4
A
B
Cert|RND|)RND|yPositionKe(hash|Dzone|Szone|ID:ABBAB sigBAABBZoneZone
Cert|)RND|yPositionKe(hash|Dzone|Szone|ID:BAABA sigBBAAZoneZone
Neighborhood distance measurement no. 1
Neighborhood distance measurement no. 2
AAAZ RND|Szone|ID|Hello:odneighborhoAN..1
PositionKey = trunc(abs(distance measurement 1 - distance measurement 2))
Mutual neighbor authentication
Mini-Project 2006 11
Neighbor map broadcasting (DSRC)
AsigADSRCDSRC eCertificat|map|ID_AreaA
Broadcasting neighbor map thought DSRC radio channel
Neighbor mapID Zone Dis AngleID Zone Dis AngleID Zone Dis AngleID Zone Dis AngleID Zone Dis Angle
MyID MySig PubKey[A]
Sig[CA] Sig[A]
Zone 8
Left side radars
Zon
e 2
Zone 1Z
one
6
Zone 5
Zone 3Zone 4
Right side radars
Fro
nt s
ide
rada
rs
Bac
k si
de r
adar
s
DSRC
radio
channel
DSRC
radio
channel
DSRC
radio
channel
Mini-Project 2006 12
Neighbor map sharing, world map assembly
G H
B C
JI
D
K
E
F
A
Phase one: Neighbor discovery+authentication (radar)
BA
F G
A`s neighbor map ID B F GZone 1 2 2Angle alfa1 alfa2 alfa3Dis(t) dis1 dis2 dis4Dis(t+1) dis2 dis3 dis5Key key1 key2 key3
BA
F G
B`s neighbor map ID C I H G F AZone 1 2 2 3 4 4Angle alfa4 alfa5 alfa6 alfa7 alfa8 alfa9Dis(t) dis6 dis8 dis10 dis12 dis14 dis16Dis(t+1) dis7 dis9 dis11 dis13 dis15 dis17Key key4 key5 key6 key7 key8 key1
BA
F G
C
H I
F`s neighbor map ID B G AZone 8 1 5Angle alfa10 alfa11 alfa12Dis(t) dis18 dis20 dis22Dis(t+1) dis19 dis21 dis23Key key8 key9 key2
Phase two: Neighbor map sharing (DSRC)
A: Neighbor map sharing
A,B,C: neighbor discovery and authentication
B: Neighbor map sharing F: Neighbor map sharing
A`s world map A->B A->G A->F B->C B->I B->H B->G B->F F->G
Angle alfa1 alfa3 alfa2 alfa4 alfa5 alfa6 alfa7 alfa8 alfa11Dist dis1 dis4 dis2 dis6 dis8 dis10 dis12 dis14 dis20
A B
F G
C
H I
Mini-Project 2006 13
Evaluation
• Necessary sensors with minimal precision
• Effect of precision on position key length
• Position error• Effect of digital signature
computation time
Mini-Project 2006 14
Environment sensors
Optical Ultrasound Lidar Radar
Automotive
Low
ran
ge
Med
ium
ran
ge
Long
ran
ge
Ala
sca
Ala
sca
XT
Vol
ksw
agen
, 24
GH
z
Toy
ota,
76
GH
z
TR
W, 7
6 G
Hz
Dai
mle
r-C
hryr
lise
r, 7
6 G
Hz
Pre
-cra
sh, 2
4 G
Hz
Par
king
rad
ar, 2
4 G
Hz
Rad
ar n
etw
ork,
76
GH
z
Sho
rt r
ang
e, 7
6 G
Hz
Med
ium
ran
ge,
10
GH
z
Long
ran
ge, 9
4.5
GH
z
Long
ran
ge, u
p to
100
GH
z
Dis
tanc
e ra
nge
Acc
urac
y by
80
m
Dis
tanc
e ac
cura
cy
MilitaryIndustrialAutomotive
ACC Imaging
Industrial
1 cm
1 m
100 m
1 km
1 m
50 cm
10 cm
1 cm 0.1 mm
1 cm
10 cm
1 m
Ade
quat
eP
oor
50 cm
5 cm
1 mm
75 cm
25 cm
5 cm
10 cm
10 m
500 m
Mini-Project 2006 15
Effect of precision on key length
Mini-Project 2006 16
Position error
Mini-Project 2006 17
Effect of digital signature computation time
Mini-Project 2006 18
Conclusion
• Independent positioning from other systems, real ad hoc network– Precise positioning (not as distance bounding)– Scalable system
• Shared map– Containing IDs, distances, speed– Therefore location of a broadcasted emergency
message is easy, collision avoidance is possible
• Strongly valuable against attacks– Position keys– Directional antennae
Mini-Project 2006 19
Back up slides
Mini-Project 2006 20
Problem statement – secure positioning in vehicular
networks
GPS s
igna
l
Your p
ositio
n is
1
A
DS
RC
broadcast
signal
I am A
,
my position is 1 B
GPS signal
Your position is 2
GPS position 1 GPS position 2
Attack
er's
GPS s
igna
l
Your p
ositio
n is
3
A
A`s map:A is at 3C is at 4
DS
RC
broadcast
signal
I am A
,
my position
is 3
B
GPS signal
Your position is 2
B`s map:A is at 3B is at 2
GPS position 1 GPS position 2A
ttacker's
DS
RC
signal
I am C
,
my position
is 4
Mini-Project 2006 21
GPS s
igna
l
Signe
dByG
PS
[You
r pos
ition
is 1]
A
B`s map:A is at 1B is at 2
DS
RC
broadcast
signal
SignedB
yA [I am
A,
my position is 1] B
GPS signal
SignedByGPS
[Your position is 2]
GPS position 1 GPS position 2
GPS signal
SignedByGPS
[Your positio
n is 3]
A
DS
RC
bro
adca
stsi
gnal
Sig
nedB
yD [I
am
D,
my
posi
tion
is 4
]
B
GPS signalSignedByGPS
[Your position is 5]
GPS position 1 GPS position 2
Wormhole channel
Wormhole channel
Wormhole channel
Mini-Project 2006 22
Synchronized positioning and authentication
HELLO
0.000s
A
B
C
Authentication
Distance measure one
D
ST
AR
T (
DS
RC
)
Broadcast neighbor
map
0,0003 0,0003 0,0003 0,0003
0,0012s
0,0073s
50x0,0003=0,0135s
Broadcast neighbor
map
Message sign
Neighbor map signMessage verify
HELLO Authentication
HELLO Authentication
HELLO Authentication
0,0036
0,0171s
Broadcast neighbor
map
Broadcast neighbor
map
Broadcast neighbor
map
Neighbor map sign
Neighbor map sign
Neighbor map sign
0,0244s
Neighbor discovery and authenticationPhase one
Neighbor map signing and broadcastingPhase two
Position changing 0,68 m
Distance measure
two
Distance measure
one
Message sign
Message sign
Message sign
Message verify
Message verify
Message verify
Mini-Project 2006 23
Zon
e 6
Zone 5
2t
Zone 7
Zon
e 2
Zon
e 6
Zone 5
Zone 3 Zone 4
2t
A
B
BAB sigBAABBZoneZone Cert|RND|)RND|)key(trunc(hash|Dzone|Szone|ID_AB
AAAZ RND|Szone|ID|Hello_tenvironmenAN..1
ABA sigBBAAZoneZone Cert|))RND|)key(trunc(hash|Dzone|Szone|ID_BA
Neighborhood distance measurement no. 1
Neighborhood distance measurement no. 2
A`s neighbor map ID JohnDoe JohnDoe2 Zone 1 7Angle Beta omegaDis(t) dis1 dis2Dis(t+1) dis2 dis3Key trunc(key) trunc(key2)
B`s neighbor map ID JaneDoeZone 1Angle BetaDis(t) dis1Dis(t+1) dis2 Key trunc(key)
B`s neighbor map ID A Zone 1Angle BetaDis(t) dis1Dis(t+1) dis2 Key trunc(key)
Zone 8Z
one
2
Zon
e 6
Zone 5
Zone 3 Zone 4
C
2t2t
A`s neighbor map ID B JohnDoe2 Zone 1 7Angle Beta omegaDis(t) dis1 dis2Dis(t+1) dis2 dis3Key trunc(key) trunc(key2)
CAC sigCAACCZoneZone Cert|RND|))RND|)2key(trunc(hash|Dzone|Szone|ID_AC
ACA sigCCAAZoneZone Cert|))RND|)2key(trunc(hash|Dzone|Szone|ID_CA
A`s neighbor map ID B C Zone 1 7Angle Beta omegaDis(t) dis1 dis2Dis(t+1) dis2 dis3Key trunc(key) trunc(key2)
Authentication without angle communication measurement
Mini-Project 2006 24
Distance measuring the radar and the measuring surface are on one axis (ideal
case)
• Since both partners are measuring the same distance it is easy to use it as a key
• The length of the key is limited by the precision of used radars
]BA[dis Vehicle A Vehicle B
RADAR
RADAR
Distance measurement A->B (radar)
Distance measurement B->A (radar)
]AB[dis key]AB[dis]BA[dis
Mini-Project 2006 25
Distance measuring problemThe radar and the measuring
surface are not on the same axes
• The radar`s position is not on the surface of the vehicle
• The radars are embedded in the front side of the vehicle
– Exact position might differ from vehicle to vehicle
– With factory calibration this problem is solvable
]BA[dis Vehicle A Vehicle B
RADAR
RADAR
Distance measurement A->B (radar)
Distance measurement B->A (radar)
]AB[dis
]AB[dis]BA[dis
keyC]AB[disC]BA[dis BA
AC
BC
Mini-Project 2006 26
Distance measuring problemwe might measure the different
distance
• Since the other vehicle front side figure (or other side) is not a standard the distance measurements might differ from each other
• The key length in this way is limited by the maximal distance measurement difference
]BA[dis Vehicle A Vehicle B
RADAR
RADAR
Distance measurement A->B (radar)
Distance measurement B->A (radar)
]AB[dis
)YX(cesin,C]AB[disC]BA[dis BA
AC
BC
X
Y
Mini-Project 2006 27
Distance measuring problem (solution one)
closest point detectionfactory calibration is necessary
• Calibrating my most exterior point (factory calibration)
– Not easy to do it precisely since sometimes the number plate is the exterior point
• Measuring neighbors closest point
– Calculating the distance between my exterior point and between its closest point
• Theoretically works but
– What if my exterior point is changed by a little accident
– Or I use a new, different number plate
]BA[dis
Vehicle A Vehicle B
RADAR
RADAR
Distance measurement A->B (radar)
Distance measurement B->A (radar)
]AB[dis
keyC]AB[disC]BA[dis BA
AC
BC
A’s exte
rior p
ointB’s exterior point
Mini-Project 2006 28
Generation of the position key - final solution
1t]BA[dis
Vehicle A Vehicle B
RADAR
RADAR
1t]AB[dis
yPositionKe]BA[dis]BA[dis21t t
2t]BA[dis
2t]AB[dis
Vehicle A
RADAR
Vehicle B
RADAR
1t
2t
21t t]AB[dis]AB[disyPositionKe
A’s clo
sest
point for B
B’s closest point for A