Vulnerabilities of Cellular and
Satellite-based Voice and Data
Networks
Dan Veeneman
dan@decodesystems.com
www.decodesystems.com/blackhat/bh-2.ppt
Focus of this talk
• Practical security problems
• Industry responses
• Lessons (hopefully) learned from mistakes
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 2
Practical Operator Considerations
• Getting paid
– Prevent (limit) subscriber fraud
– Ensure accurate clearing with other operators
•
•
•
•
•
Reduce churn
Ensure sufficient capacity
Provide CALEA compliance
Maintain public perception of security
Provide additional features (marketing)
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 3
Cellular
•
•
•
•
Analog
Digital - TDMA
Digital - CDMA
Digital - GSM
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 4
Cellular Signaling
• Control channel
– Forward is continuous
– Reverse is shared
• Voice (Traffic) channel
– Assigned for the call
– Shared in digital systems
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 5
Analog Cellular
• Authentication is valid Electronic Serial
Number (ESN) and Mobile Identification
Number (MIN) pair
• Sent from mobile to base in the clear
• Early systems had just a “deny” list
• Not all systems initially available to each
other for roaming verification
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 6
Phone Theft
• Automobile “smash and grab”
• Use until service is canceled
• Call-sell operations
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 7
Database Theft
•
•
•
•
Dumpster diving
Insider account maintenance
Hack into authorization database
Hack into switch maintenance port
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 8
Rogue Base Station
• Forward link has no
authentication
• Mobiles lock to false
outbound
• Cell phone suppressor
• Test equipment (ESN
readers)
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 9
Network Interception
• Read pairs on link between base station and
switch
• Microwave in many areas
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 10
Tumbling
•
•
•
•
ESN/MIN pair sent to home system
Pre-call validation not available
First call allowed to go through
“Tumble” through random ESN/MIN pairs
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 11
Cloning
• Replace legit ESN with
snarfed ESN
• Reprogram MIN
• “Extension” phones
• Rewrite phone firmware
• (Chip in lower left corner is
conveniently socketed)
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 12
Snarfing
• Tune scanner to control
channel
• Decoder monitors inbound
data
• Computer stores
ESN/MIN pairs when the
mobile registers
• AMPS data is simple
FSK, in the clear
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 13
Subscription Fraud
• Sign up for service under false identity
• “Identity Theft”
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 14
Session Hijacking
• Overpower base
station during
legitimate call
• Use cell phone test
mode to match
Supervisory Audio
Tone (SAT)
• Flashhook and place
another call
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 15
Fighting Analog Fraud
• Legal
– Illegal to eavesdrop
– Illegal to clone
– Illegal to possess equipment that might be used to clone
• Technical
– PINs
• Customers hated this
– Velocity checks
• Good for roaming, not great for local clones
– Don’t allow more than one active at a time
– RF Fingerprinting
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 16
2G Authentication
• Generally, mobile is given a challenge and network
checks the response
• US Digital Cellular
– Cellular Authentication and Voice Encryption (CAVE)
– Control Message Encryption Algorithm (CMEA)
– Voice Privacy Mask (VPM)
• GSM
– A3 Authentication
– A8 cipher key generation
– A5 privacy
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 17
Cellular Authentication and Voice
Encryption
•
•
•
•
A-key, 64 bits (20 digits plus 6 check digits)
RANDSSD: 56 bits
Electronic Serial Number (ESN): 32 bits
Shared Secret Data (SSD)
– SSD_A: 64 bits, for authentication
– SSD_B: 64 bits, for encryption
• Authentication Result, AUTHx: 18 bits
• Unique Challenge
– Uses voice channel during call attempts
• Global Challenge
– Uses control channel, checks during registration, call attempt and
call delivery
– All phones challenged with the same number
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 18
Authentication
• Phone attempts to access the
network
– indicates authentication capability
• Serving MSC contacts HLR and
AC
– indicates whether it can do CAVE
• (if not, SSD cannot be shared, AC
must do all the work)
– Gets profile
• Includes whether authentication
should be done
– Generates random number RANDU
and sends it to phone
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 19
Authentication
• Phone runs CAVE ( RANDU,
SSD, MIN, ESN )
– Produces AUTHU
– Sends AUTHU to MSC
• MSC runs CAVE ( RANDU,
SSD, MIN, ESN )
– Produces local AUTHU
• At MSC, if received AUTHU
matches local AUTHU,
authentication is successful
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 20
Shared Secret Data Update
• Phone and AC update their SSD
– AC generates RANDSSD
• Sends it to Serving MSC
• Computes SSD from RANDSSD, ESN, A-key
– MSC sends RANDSSD to phone
– Phone generates SSD from RANDSSD, ESN, A-key
• Phone authenticates Base Station (or AC)
–
–
–
–
–
–
–
Generates RANDBS
Calculates AUTHBS from RANDBS and new SSD
Sends RANDBS to Serving MSC
Either MSC or AC uses RANDBS and new SSD to calculate AUTHBS
MSC sends AUTHBS to phone
If phone AUTHBS and MSC AUTHBS match, phone stores new SSD
Another authentication process is performed
• If successful, AC stores new SSD
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 21
Count
• Mobile maintains a 6-bit COUNT variable
• Incremented on instruction from AC
• AC maintains COUNT for each mobile
• COUNT values must match in order for
mobile to gain access
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 22
Weaknesses
• Information sent in the
clear on interconnection
networks (SS7, etc)
• Secret information held in
vulnerable locations (HLR,
VLR, etc)
• CMEA “broken”
• Small keysize
• Poor A-keys
• VPM fixed for the length
of the call
– XOR against known voice
(e.g. silence)
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 23
Global System for Mobiles
• Handsets and SIMs
• International Mobile
Equipment Identifier
(IMEI)
• International Mobile
Subscriber Identity
(IMSI)
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 24
GSM Network Elements
•
•
•
•
•
•
•
•
•
•
AuC: Authentication Center
BTS: Base Transceiver Station
BSC: Base Station Controller
EIR: Equipment Identity Register
(white, black, grey)
HLR: Home Location Register
ME: Mobile Equipment
MSC: Mobile Switching Center
OMC: Operations & Maintenance
Center
SIM: Subscriber Identity Module
Visitor Location Register
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 25
GSM Security Goals
The objective of security for GSM system is to make the system as secure as the
public switched telephone network. The use of radio at the transmission media
allows a number of potential threats from eavesdropping the transmissions. It was
soon apparent in the threat analysis that the weakest part of the system was the radio
path, as this can be easily intercepted.
The GSM MoU Group produces guidance on these areas of operator interaction for
members. The technical features for security are only a small part of the security
requirements, the greatest threat is from simpler attacks such as disclosure of the
encryption keys, insecure billing systems or corruption ! A balance is required to
ensure that these security processes meet these requirements.
At the same time a judgment must be made of the cost and effectiveness of the
security measures.
Charles Brookson
Chairman GSM MoU Security Group
Mercury one2one
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 26
Anonymity
• Temporary identifiers.
• When a user first switches on his radio set,
the real identity is used, and a temporary
identifier is then issued.
• From then on the temporary identifier is
used.
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 27
Authentication
• A random challenge is issued
to the mobile
• Mobile encrypts the challenge
using the authentication
algorithm (A3) and the key
assigned to the mobile (Ki)
• Mobile sends response back
(SRES)
• Network checks that the
response to the challenge is
correct.
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 28
User data and signaling privacy
• A8 algorithm to compute
Kc
• Used to encrypt the
airlink
• A5 series privacy
algorithms
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 29
Cryptographic Algorithms
• A3 and A8 are in the SIM
– Operators can choose their own A3/A8
– COMP-128 provided as example algorithm
– Can securely pass (RAND,SRES,Kc) while
roaming
• A5 is built into the hardware
– A5/1 - more secure
– A5/2 - less secure
– Unencrypted
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 30
GSM weaknesses
• COMP-128 leaks Ki (April 1998)
• A8 has effective security of 54 bits
– (last 10 bits set to 0)
• A5
–
–
–
–
64-bit key (Kc) and 22-bit frame number, three shift registers
A5/1 (western Europe)
A5/2 (used in North America)
A5/0 (no encryption)
• Rogue base station
• Unencrypted network links
– Eavesdropping
– Query HLR/AuC for new triples
• Kc refreshed only occasionally
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 31
Subscriber Identity Module
• C1: Supply voltage
– (4.5 to 5.5 volts DC).
• C2: Reset signal
• C3: Clock signal
– (1 to 5 MHz, external)
• C4: Reserved
• C5: Ground
• C6: Programming voltage
– (if available)
• C7: Input/Output
– Baudrate is (clock
frequency) / 372.
• C8: Reserved
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 32
Talking to a SIM
• Defined by ETSI document GSM 11.11
• Five bytes:
– Class of instruction (CLA)
• (always 0xA0 for GSM)
–
–
–
–
Instruction Code (INS)
Parameter 1 (P1)
Parameter 2 (P2)
Parameter 3 (P3)
• (length of optional data segment)
• SIM card readers may require additional bytes
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 33
Listening to a SIM
• Three fields:
– Data
• (variable length)
– Status Word 1 (SW1)
– Status Word 2 (SW2)
• 90 00 is normal response
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 34
SIM Commands
COMMAND
SELECT
STATUS
READ BINARY
UPDATE BINARY
READ RECORD
UPDATE RECORD
SEEK
INCREASE
VERIFY CHV
CHANGE CHV
DISABLE CHV
ENABLE CHV
UNBLOCK CHV
A4
F2
B0
D6
B2
DC
A2
32
20
24
26
28
2C
INS
00
00
offset
offset
record
record
00
00
00
00
00
00
00
INVALIDATE
REHABILITATE
RUN GSM ALG
SLEEP
FA
GET RESPONSE
04
44
88
00
C0
00
00
00
00
00
Black Hat Briefings
July 31, 2002
P1
(high)
(high)
number
number
P2
00
00
offset (low)
offset (low)
mode
mode
type/mode
00
CHV number
CHV number
01
01
00 (for CHV1)
02 (for CHV2)
00
00
00
00
00
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
P3
02
length
length
length
length
length
length
03
08
10
08
08
10
10
00
00
00
length
Page 35
SIM Conversation
Setup card for access
Activating card...01
Sending ATR 1...
Sending Inverse ATR 1...3F 2F 00 80 69 AF 02 04 01 31 00 00 00 0E 83 3E 9F 16
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 36
SIM Conversation
Read Master File
A0 A4 00 00 02
Select file
A4
ok
3F 00
Master File
9F 16
file access ok, 0x16 byte response
A0 C0 00 00 16
Read 0x16 byte response
C0 85 14 00 00 3F 00 01 80 FF FF FF 43 09 89 03 09 04 00 83 8A 83 8A 90 00
Master File Header
[MF/DF] RFU: 85 14
Free Memory: 00 00
File ID:
3F 00 (MF)
File Type:
01 (Master File)
RFU:
80 FF FF FF 43
Length:
09
File characteristics:
89
Clock stop:
Allowed, low level preferred
Required speed: 13/8
CHV:
Disabled
Child DFs:
03
Child EFs:
09
CHVs, Unblock CHVs, etc: 04
RFU:
00
CHV1 Status:
83 (Initialized, 3 remaining)
Unblock CHV1 Status:
8A (Initialized, 10 remaining)
CHV2 Status:
83 (Initialized, 3 remaining)
Unblock CHV2 Status:
8A (Initialized, 10 remaining)
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 37
SIM Conversation
Read Dedicated File
A0 A4 00 00 02
A4
7F 20
9F 16
A0 C0 00 00 16
C0 85 14 00 04 7F 20 02 00 FF FB FF 23 09 99 00 19 04 00 83
Select file
ok
GSM Dedicated File
access ok, 0x16 byte response
Read 0x16 byte response
8A 83 8A 90 00
Dedicated File Header
[MF/DF] RFU: 85 14
Free Memory: 00 04
File ID:
7F 20 (DF-GSM)
File Type:
02 (Directory File)
RFU:
00 FF FB FF 23
Length:
09
File characteristics:
99
Clock stop:
Allowed, low level preferred
Required speed: 13/8
CHV:
Disabled
Child DFs:
00
Child EFs:
19
CHVs, Unblock CHVs, etc: 04
RFU:
00
CHV1 Status:
83 (Initialized, 3 remaining)
Unblock CHV1 Status:
8A (Initialized, 10 remaining)
CHV2 Status:
83 (Initialized, 3 remaining)
Unblock CHV2 Status:
8A (Initialized, 10 remaining)
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 38
SIM Conversation
Read Elementary File
A0 A4 00 00 02
A4
6F 07
9F 0F
A0 C0 00 00 0F
C0 85 0D 00 09 6F 07 04 00 1B FF 1B 23 02 00 00 90 00
Elementary File Information
[EF] RFU:
85 0D
File Size:
00 09
File ID:
6F 07 ((GSM) EF-IMSI)
File Type:
04 (Elementary File)
RFU:
00
Access:
1B FF 1B
Read/Seek:
CHV1
Update:
Admin 11
Increase:
Never
RFU:
Never
Rehabilitate: CHV1
Invalidate:
Admin 11
Status:
23 (Not Invalidated)
Length:
02
EF Structure: 00 (Transparent)
Record Length: 00
A0 B0 00 00 09
B0 08 39 01 13 10 00 43 98 44 90 00
Black Hat Briefings
July 31, 2002
Select file
ok
(GSM) EF-IMSI
access ok, 0x0F byte response
Read 0x0F byte response
Read file, 9 bytes
IMSI
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 39
SIM Conversation
Select GSM Dedicated File
A0 A4 00 00 02
A4
9F 16
Perform A3A8
A0 88 00 00
88
00 00 00 00
9F 0C
A0 C0 00 00
C0 D0 70 89
computation
10
Perform A3A8
A0 88 00 00
88
00 00 00 00
9F 0C
A0 C0 00 00
C0 9B 8E 05
computation
10
Select File
ok
GSM Dedicated File
00 00 00 00 00 00 00 00 00 00 00 00
0C
C4 8F 23 C4 EB 59 78 EC 00 90 00
00 00 00 00 00 00 00 00 00 00 00 01
0C
84 FF 8A E8 60 45 A7 30 00 90 00
Black Hat Briefings
July 31, 2002
A3A8 with 0x10 bytes
ok
RAND challenge
ok, 0x0C bytes waiting
get response
A3A8 with 0x10 bytes
ok
RAND challenge
ok, 0x0C bytes waiting
get response
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 40
SIM attacks
• Repeated authenticate, leaks Ki
– (New SIMs have a limit (about 50k) on the
number of times the authentication algorithm
can be run)
• Side-channel attacks
– Power consumption
– Timing
– Electromagnetic emanations
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 41
COMP-128 Updates
• COMP128-2
– 54-bit Kc
– Secret algorithm
• COMP128-3
– 64-bit Kc
– Secret algorithm
• Proposal for new A3A8 based on MILENAGE
– Milenage based on Rijndael (AES)
– Algorithm will be public
• New A3A8 requires
– AuC software upgrade
– New SIMs
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 42
A5/3
• Based on the Kasumi algorithm
– 3GPP confidentiality and integrity algorithms.
• Kasumi derived from the MISTY algorithm,
created by Mitsubishi.
• Specifications are publicly available on the
3GPP web site (www.3gpp.org).
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 43
Cellular Jamming
• Low-power private base station transmits a forward link overhead
message
• Mobiles register with base station
• Base station never sends a page
• The FCC view on this:
•
•
The Communications Act of 1934, as amended, and the Commission's rules do not permit the use of
transmitters designed to prevent or jam the operation of wireless devices in hospitals, theaters and
other locations. Section 302(a) of the Communications Act, 47 USC 302(a), prohibits the manufacture,
importation, sale, offer for sale, or use of devices that fail to comply with the regulations promulgated
pursuant to this section.
Based on the above, the operation of transmitters designed to jam wireless communications is a
violation of 47 USC 301, 302(a), and 333. The manufacture, importation, sale or offer for sale, including
advertising, of such transmitters is a violation of 47 USC 302(a). Parties in violations of these provisions
may be subject to the penalties contained within 47 USC 501-510. Fines for a first offense can range as
high as $11,000 for each violation or imprisonment for up to one year. The equipment can also be seized
and forfeited to the U.S. Government. These regulations apply to all transmitters that are designed to
cause interference to, or prevent the operation of, other radio communication systems.
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 44
Satellite Networks
• Big LEOs
• Little LEOs
• Mobile Satellite
Ventures
• INTELSAT
• INMARSAT
• VSAT
• GPS
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 45
Big LEO
• Constellation of satellites in Low Earth
Orbit (as opposed to geosynchronous)
• Base stations in the sky
• Linked to network of ground stations
• Voice as primary service
• 1610 to 1626.5 MHz up
• 2483.5 to 2500 MHz down
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 46
Iridium
• $5 billion
• 66 satellites (plus spares)
• TDMA, processing onboard
• 1621.35 to 1626.5 up and
down
• 2.4 kbps data service
• Service start November
1998
• Bankruptcy in August
1999, only 55,000
customers
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 47
Iridium Satellite LLC
•
•
•
•
•
Paid $25M for Iridium assets
Relaunched commercial service in 2001
Large government contract ($72M/2 years via DISA)
Dedicated gateway earth station in Hawaii
Defense Information Systems Agency
– Department of Defense
– Department of State
– Inter-satellite links
• Enough money to replenish satellites?
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 48
Globalstar
• Loral, Qualcomm
• 48 satellites in LEO
• Start of operations
February 2000
• Currently under
bankruptcy protection
• Bent-pipe
• CDMA service
• Underpowered satellites
– Recharge over oceans
• 9.6 kbps data
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 49
ICO
• $4.7 billion
• Hughes-built satellites
• 10 satellites in Medium
Earth Orbit (MEO)
• GSM-based
• New ICO
• Craig McCaw
• Merged with Teledesic
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 50
Orbcomm (Little LEO)
•
•
•
•
•
28 satellites
14 earth stations
VHF operation
Data only
Store and Forward if
ground station not in view
• “GlobalGrams” = X.400
e-mail
• Latency
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 51
Mobile Satellite Ventures
• Motient
– AMSC-1 ($500M)
– Spar Aerospace
• TMI
– MSAT-1 (identical)
• Mobile satellite voice and
data
• L-band
• Digital voice
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 52
Interception
• Gateways require tapping
–
–
–
–
–
FBI, CALEA requirements
Iridium agreement
Globalstar agreement
TMI on-demand access
National intelligence and police forces
• Test equipment
• Limited use of encryption
• Modifiable phone equipment
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 53
INTELSAT
•
•
•
•
•
•
Was a consortium of nations as signatories
Now privatized
Large fleet in geostationary orbit
Primarily telephone and television traffic
Carries unencrypted voice, data and fax
Used by US DoD for UAV datalink
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 54
INMARSAT
• International Maritime Satellite Organization
• AOR, POR, IOR coverage
• L-band
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 55
Global Positioning System
• 24 satellites
• Selective Availability
turned off May 2000
• 30 meter accuracy
• Can be jammed
(denial of service)
• Can be spoofed
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 56
GPS Frequencies
L1: 1575.42 MHz: Coarse Acquisition (C/A) code
L2: 1227.60 MHz: Precise (P) or Y (encrypted) code
L3: 1381.05 MHz: Nuclear burst detectors
L4: 1841.40 MHz: Ionospheric correction (under study)
L5: 1176.45 MHz: Civilian safety-of-life signal (proposed)
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 57
GPS Enhancements
The new architecture also requires new user equipment and an
upgraded ground control segment, as well as M-Code. All of those
elements should be in place by 2008, when 18 satellites with MCode - 12 IIRs and 6 IIFs - will be up.
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 58
GLONASS
• Global Orbital Navigation Satellite System
• 1606 to 1616 MHz
• Full operational status achieved once
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 59
Satellite Failures
• PanAmSat Galaxy 4
– Attitude control and backup failed
– Major supplier of service to paging towers
• AT&T Telstar 401
– launched 1993, failed 11 January 1997
– abrupt failure, solar activity? (large solar flare 6 January 1997)
• Galaxy 7
– Primary control processor failed June1998. Secondary processor
failed November 2000.
– Suspected electrical shorts in spacecraft control processor (SCP).
• Solidaridad 1
– Primary SCP failed May 1999. Secondary SCP failed August 2000.
• Anik E1
– 1996, Power Subsystem Failure, Partial Loss
• EchoStar 4
– 1998, Solar Array Failed to Deploy, reduced electrical power available
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 60
Questions?
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 61
Satellite Glossary
BEACON
Modulated oscillator, usually containing telemetry. Sometimes referred to
as a “pilot.” Used to locate a satellite and determine received signal strength.
BEAM
Uplink or downlink channel to or from the satellite. May cover a wide area, or be
focused on a particular location (“spot beam”).
BENT PIPE
Big repeater in the sky. Simply repeats uplinked signal on downlink side, with
amplification. Also called non-processing.
DOWNLINK, UPLINK
Downlink is signal from satellite to ground station.
Uplink is signal from ground station to the satellite.
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 62
Satellite Glossary (con’t)
EOL
End of Life. Satellite lifetimes, barring accident or other damaging
incident, are determined by the amount of maneuvering fuel (typically
hydrazine) on-board. When the fuel runs out the satellite can no longer
be maneuvered to stay in it's assigned orbital location. The orbit then
becomes inclined. Current satellites have an expected life of 10 - 15 years.
ECLIPSE
Satellite's solar panels are blocked by the earth (22 days before and after spring
and autumn equinox, maximum of 70 minutes) or the moon (irregular).
EIRP
Effective Isotropic Radiated Power. A measure of satellite transmitter strength,
usually in dBw (decibels above one watt).
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 63
Satellite Glossary (con’t)
FDMA, TDMA, CDMA, DAMA
Modulation schemes to allow resource (bandwidth) sharing.
Frequency Division Muliple Access: standard for video.
Time Division Multiple Access: standard for telephone, most data.
Code Division Multiple Access: spread spectrum, originally military.
Demand Assign Multiple Access: shared data systems, including VSAT.
FEEDERLINK
Communications link between the ground station and the satellite.
This link is distinct from the user links.
FOOTPRINT
Geographic area on the earth covered by a particular satellite beam.
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 64
Satellite Glossary (con’t)
INCLINED ORBIT
When maneuvering fuel runs out. Requires tracker at ground station.
Traces a figure-eight pattern above and below the equator over 24 hours.
INMARSAT
International Maritime Satellite Organization.
Covers Atlantic (AOR East and West), Pacific (POR) and Indian (IOR) Oceans.
Has spares in orbit, not always in contact with TT&C.
LOOK ANGLE
Elevation from a given location to a satellite. 90 degrees is directly overhead,
0 degrees is on the horizon.
PSEUDOLITE
Pseudo-satellite. Ground-based or airborne transmitter emitting satellite-like signals.
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 65
Satellite Glossary (con’t)
TRANSPONDER
Discrete frequency slot assigned to an uplink/downlink.
TT&C
Telemetry, Tracking and Command. Ground Station monitoring and controlling
satellite operation.
TWT
Traveling-Wave Tube amplifier. Has nearly flat response across a wide bandwidth.
Newer satellites are using solid state amplifiers.
VSAT
Very Small Aperture Terminal. Usually dedicated data links in a star configuration.
Popular with gas stations for credit card verification; car dealers for sales information.
Black Hat Briefings
July 31, 2002
Vulnerabilities of Cellular and Satellitebased Voice & Data Networks
Page 66