Vamsikrishna AmbatiKokil BhaleraoChandra S.CherukuHariPriya ChintalapatiNagaKalyani PadakantiShveta Shahi
Security in RFID
Presented By… NetSecurity-Spring07
What is RFID??
RFID System Components
Architecture
Applications
Security Issues and Challenges ……
Conclusion
Presentation Objectives
RFID (Radio Frequency Identification) uses a micro-chip in a tag to transmit stored data when the tag is exposed to radio waves of the correct frequency.
What is RFID ??
Tag wirelessly sends bits of data when it is triggered by a reader.
Reader transmits radio frequency energy• Provides power for the tag.• Enables communications to and from the tag.• Different operating frequencies are possible.
System of tags, readers, antennas, and software.
RFID systems are composed of three key components..
• The RFID tag, or transponder, carries object identifying data.
• The RFID tag reader, or transceiver, reads and writes tag data.
• The back-end database stores records associated with tag contents.
RFID System Architecture…
Passive RFID Active RFID
Tag Battery No Yes
Availability of power Only in field of reader Continuous
Signal Strength Very High Very Low
Range Up to 3-5m Up to 100m
Tags can be active or passive.
RFID Tags..
Antenna
Active Passive
RFID Applications.. Personal Productivity
• Automatic toll collection• Ticketing and event access• Library checkout
Other Applications
• Automobile Keyless entry • E-Passport
RFID Challenges.. • The Privacy Problem
Wigmodel # 143 (cheap polyester)
$ 1000 in wallet30 Items of
candies
Hacking BOA
• Security• Reader Collision• Tag Collision • Signal Interference in noise • Inconsistent data
RFID Security Issues User Privacy
Replay Attack
Virus Injection
Denial of service
Tag Cloning
User Privacy
Few concerns related to user privacy• Products labeled with insecure tags may reveal sensitive information.• Location privacy violation which may lead to tracking of individual by the
tags they carry.
• RFID passport have signed biometric stored in RFID chip. When there read request it just return the stored value. This signal can be captured and a device can be made to replay the same signal which may seem to come from valid RFID passport.
Replay Attack
Security Concern with replay attack:
Virus can be injected while data is in transit
Concerns with virus injection:• Tags scanned after the database is infected can also be infected with
the virus.• A malicious activity like dropping database tables is possible.
Virus Injection
Denial Of Service Concerns with denial of service:
• Thieves could remove tags or put in foil-lined booster bag that will block RFID reader’s request and temporarily deactivate the tag.
• An attacker could attach RFID on other items causing RFID system to record useless data which will flood an RFID system with more data then it can handle.
Tag Cloning
Ability to spoof tags to overwrite the data in tags, overwrite the tag ID.
A data integrity attack.
Few security concerns• Replace the tag for an expensive item with the tag of cheaper item.
• Switching two books’ RFID data or changing the security status of the tags.
Solutions to security issues
Kill Tag
Smart RFID Tag
Blocker Tag
DST Tag
Authentication Protocol• Simplified Authentication protocol• Enhanced Authentication protocol
The Kill Tag Approach….
• Used to protect consumer privacy. • The RFID tag of the object is killed by sending a special
‘kill’ command to the tag.• A killed tag can never be reactivated.• Example: An RFID tag is killed by check out clerk before the
object is given to customer.• Drawback:
• It is undesirable in many environments.• Many applications require the tag to be active even after purchase.
Smart RFID Tags
• Protect consumer privacy while RFID tag remains active.• Types of smart RFID tag: Hash Lock Approach…. Simple access control mechanism based on one way hash function.
Randomization Hash Lock Approach…. Similar to hash lock but a random number generator is also embedded along with one way hash function.
Hash Lock: Locking protocol
1. Reader R selects a random key and computes metaID = hash(key).
2. R writes metaID to tag T.
3. T enters the locked state.
4. R stores the pair(metaID, key) locally.
Hash Lock Approach: unlock
Reader Tag
querymetaIDmetaID
database (key,metaID)KeyID
Strength of Hash lock Approach• Prevent unauthorized reader from reading the tag because of one-wayness of hash
Weakness of Hash lock Approach• The unauthorized reader can keep track of tag using metaID.
Randomized Hash lock: unlock
Reader Tag
query
R,h(IDk||R)Get all ID’s
database ID1, ID2….IDk IDk
Strength of Randomized Hash lock Approach Address the problem of tracking tags by their metaID
Weakness of Randomized Hash lock Approach Impractical for reader with large number of ID’s
Blocker Tag..• A blocker tag prevents RFID tags from being read• RFID reader can read one tag at a time• Reader will unable to read information if more than one tag
responses• A blocker tag takes advantage of this technique to block the
reader• When a reader try to read a tag belonging to a privacy zone, then
the blocker tag confuses the reader by always responding• This way, blocker tag blocks any tag from being read.• Weakness of Blocker tag
– It can be used as malicious tool.Digital Signature Transponder• It uses cryptographic mechanism in wireless authentication
applications• It acts as a passive transponder and implements a challenge-
response authentication using block cipher• A DST tag contains non-volatile RAM to store 40-bit encryption
key.
DST algorithm
Reader(40-bit
encrypt. Key)
Tag(40-bit
encrypt. Key)
1.40-bit challenge 2. Encipher to 40-
bit Cipher text3. Truncates to 24-bit
response5. Calculates expected challenge
6. Compares calculated challenge with tag response
4. 24-bit response
Simplified Authentication Protocol
Tag Readerh(IDi), N, hIDi (N)
Request
Strength of Simplified Authentication Protocol• Provides protection against tracking, tag cloning and it
also provides forward security.
Weakness of Simplified Authentication Protocol• Replay Attack• Database De-synchronization
ID h(ID)
XXX yyy
aaa bbb
Enhanced Authentication Protocol
Request,NR
H(Idi),NT,hIDi(NT,NR)
hIDi+1(NT,NR)
Strength of Enhanced Authentication Protocol• Tag cannot be attacked because if attacker is masquerading as
reader then he will not know the shared secret which is ID of the tag.
• Reader cannot be attacked because of the shared secret. • Which protects against replay and database de-
synchronization attack.• The communication between tag and reader cannot be attacked
because of one-way of hash.• User privacy cannot be attacked because no identity is released by
the tag.• Location privacy cannot be attacked because ID value changes with
every read.
ReaderTag
ID h(ID)
XXX yyy
aaa bbb
Conclusion
• RFID definitely has some security issues that need to be addressed.
• According to latest report from Texas Instruments there is no fraud reported with DST approach in last eight years.
• In enhanced authentication protocol, both reader and tag are authenticated by each other.
• Enhanced authentication protocol is most secure solution and uptill now we didn’t identify any weakness associated with this protocol.
References• http://www.rfidjournal.com/article/articleview/
549/1/1/• http://en.wikipedia.org/wiki/
Digital_Signature_Transponder• Stephens August Weis, " Security and Privacy in
Radio-Frequency Identification Devices”• Ari Juels and Ronald L. Rivest and Michael
Szydlo, "The Blocker Tag: Selective Blocking of RFID Tags for Consumer Privacy”
Any Questions
Thank U………..