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RFID
RFID
57
Computer Science
04/15/2012

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Cards

Term
How does the RFID antenna-loop work
Definition
Reader generates a field, this is used by the transponder to load it's condensator.
Term
2. What are the methods of people based RFID tagging (5)
Definition
• Access control and tracking and tracing of individuals
• Loyalty, membership and payment
• eHealth care
• Sport leisure and household
• Public services
Term
3. What is Verichip?
Definition
A chip to be planted underneath human tissue for tracking purposes
Term
4. What are some privacy concerns for RFID (4)
Definition
• Worldwide unique IDs enable tracking
• Unnoticed remote reading without line-of-sight
• Tracking and profiling through sporadic surveillance
• Small hidden tags and readers
Term
5. What are the 6 stages of RFID operation?
Definition
• Reader broadcasts signal through antenna
• Tag receives signal and gets charged
• The charged tag sends identifying response back to the reader
• Antenna reads the data and sends to reader
• Reader sends data/info to computer for processing
• Computer sends event based data to be stored on tag
Term
6. What are the 3 major components of RFID systems
Definition
• The RFID tag (transceiver and receiver)
• The RFID Reader (transponder)
• The data processing subsystem
Term
7. What are the 2 stages of RFID interaction?
Definition
• RFID reader generates a field to activate the tag.
• The tag modulates the RF signal using transistor data, which sends data
Term
8. What are the 3 different RFID tag types?
Definition
• Passive
• Semipassive
• Active
Term
9. How do they each work?
Definition
• Passive – user the power transmitted from the reader for the microcontroller and for transmission
• Semi-passive – a battery is used for the microcontroller, the readers power is used for transmission
• Active – a battery is used to power microcontroller and transmission
Term
10. What are the 3 RFID storage types and how do they work?
Definition
• Read-write: tags data can be added or overwritten
• Read-only: cannot be added to or overwritten, they contain only the data that is stored in them when they were produced
• WORM (write once, read many) tags can have additional data added once, but they cannot be overwritten.
Term
11. What are 5 data transfer coding principles?
Definition
• Non Return to Zero (NRZ) – Signal 1 = “1”, signal 0 = “0”
• Return to Zero (RZ) - Return to zero = 1; signal 0 = “0”
• Manchester - Step from 1 to 0 = 1, step from 0 to 1 = 0
• Pulse Width Modulation (PWM) - Information is in the pulse width
• Pulse Position Modulation (PPM) - Pulse position marks “1” bit
Term
12. What are the 4 frequency bands?
Definition
• Low
• High
• Ultra High
• Microwave
Term
13. What does EPC stand for?
Definition
Electronic Product Code standards
Term
14. What topics do EPCglobal and ISO have in common?
Definition
• Security and Privacy
• Data Format and Structure
• RFID Process and control and RFID Application access Layer
• Data Management
• Device Interface
• Device Management
• Air Interface
Term
15. What is “useless data”
Definition
Error messages generated by a tag, or information generated by a tag responding to requests not made to it
Term
16. What are two methods for handling useless data and how do they work?
Definition
Smoothing – Ignoring temporary data inconsistencies to avoid generating meaningless events

Filtering – Reporting only on tags that match predefined data
Term
17. What is middleware?
Definition
Found between the tag and the central server, the middleware identifies services within a certain area to ensure that they’re available
Term
18. What are the three levels of EPC Tag Data?
Definition
Header
Filter Value
Domain Identifier
Term
19. What is singulation?
Definition
When an RFID reader identifies a tag with a specific serial number from a number of tags in its area
Term
20. Singulation causes which problem?
Definition
If multiple tags respond simultaneously to a query, they will interfere with each other.
Term
21. Explain “tree walking”
Definition
• Start by asking for the first bit of the required serial number
• Ask all respondents for the second bit
• Continue until finished
Term
22. What are some problems with Tree walking (2)
Definition
Considerable information leak
Can be blocked by RSA security blocker tags
Term
23. Explain two collision avoidance techniques
Definition
ALOHA protocol – Tags detect collisions that occurred and resend their messages after waiting a random interval. Less effective with more tags, too many may cause collapse / congestion. Works for around 200 tags per second

Slotted ALOHA – introduced discrete timeslots to reduce collisions
Term
24. List 5 EPC classes
Definition
• Class 5 – Readers. Can power classes 1 2 and 3, communicate with class 4, and with other class 5s wirelessly
• Class 4 – Active tags. Broadband peer to peer communication with other tags in the same frequency tag and with readers
• Class 3 – Semi passive RFID tags, supporting broadband
• Class 2 – passive tags including memory or encryption
• Class 1 / 0 – read only passive
Term
25. Two RFID authentication password types:
Definition
Lock – to protect the tag from unauthorised writing
Kill – deletes important information on a tag
Term
26. 5 RFID attacks on confidentiality
Definition
• Eavesdropping
• Tracing/Tracking
• Skimming tag data
• Interrogation
• Decryption
Term
27. Tracking analyses for which 4 values:
Definition
• Communication patterns
• Data
• Time
• Location
Term
28. Three rules for skimming:
Definition
• 16 x power = 2 x distance
• Limited due to noise levels
• Practical limit around 20 x distance, using a proper antenna
Term
29. Data integrity of an RFID tag is vulnerable where (2)
Definition
• Data stored on RFID tag
• Transmission signal of transceiver or responder may be duplicated or corrupted
Term
30. Two integrity attacks:
Definition
• Spoofing – send duplicated / corrupted data to the reader
• Cloning – duplicating tags (data)
Term
31. How does spoofing operate (4)
Definition
• Duplicate data and trx to reader
• Read and store UID and memory data from tag
• Emulate tag using UID and memory data
• Change memory data as desired
Term
32. What are three countermeasures against RFID attacks?
Definition
• Authentication between tag and reader
• Encryption of the data transfer between tag and reader
• Proper key management – key generation, session keys, key updates
Term
33. Four availability attacks on RFIDs
Definition
• Shielding/absorption/detuning – mechanical disruption
• Jamming – using electro-magnetic signals
• Physical destruction
• Overload via DOS
Term
34. How does a blocker tag function?
Definition
By sending both a 0 and a 1 bit simultaneously, forcing a collision and making the reader search the entire tree
Term
35. Are RFIDs susceptible to viruses?
Definition
Yes
Term
36. What are Zhang and King (2005)s RFID security evaluation guidelines? (3)
Definition
• Is the modification of tag data protected by an authorisation function?
• Can an authorised party determine whether or not a tag still contains authentic tag information?
• Can an authorised party recognise between authorised and fake tags?
Term
37. Advantages of RFIDs (3):
Definition
• Inventory efficiency
• Good ROI
• Damage resistant (vs barcode)
Term
38. Disadvantages of RFIDs (7):
Definition
• Signal coverage
• Proximity issues – influence of metal and other materials
• Weak vs water and high magnetic fields
• Security concerns
• Ghost tags – reading of inexistent tags
• Unread tags – sometimes tags are overlooked
• High costs – still relatively expensive
Term
39. How can the ghost tag issue be resolved?
Definition
Using cyclic redundancy checks in generation 2 RFID tags
Term
passive tags use what power
Definition
the power transmitted from the reader for the microcontroller and for transmission
Term
semipassive tags use what power
Definition
battery is used for the microcontroller only. The energy received from the reader is used for the transmission.
Term
what length are the rfid passwords now
Definition
32 bits
Term
how long did rfid passwords used to be
Definition
8 bits
Term
distance of rf tags
Definition
3-9meters
Term
UHF - Tag -> Reader transmission power and distance
Definition
0, 1-1mW:10-30m
Term
UHF - Reader -> Tag (range and power)
Definition
2w:100m
Term
tracking / tracing is
Definition
Eavesdropping for a certain amount of time
Term
what do you analyse when tracking / tracing?
Definition
communication patterns,
data,
time,
location.
Term
Shielding does what
Definition
inhibits the comms by limiting / reducing the generated / received electro-magnetic fields
Term
Absorption is
Definition
Many materials also absorb electromagnetic energy and convert it into heat
Term
Detuning is
Definition
once a transponder is put together with an object the behavior of the antenna or coil will change because of the proximity of materials
Term
Jamming range for 60mW
Definition
20m
Term
Jamming range for 250mW
Definition
50m
Term
Jamming range for 1W
Definition
100m
Term
Blocker tag works by
Definition
When a reader asks for the next bit value it broadcasts both a 0 and a 1 bit
Term
Relay attack is
Definition
reader stealing a link and link 'over distance' to an emulator
Term
What's missing from ISO but is in EPC
Definition
Air interface security