What is a Radio-Frequency Identification (RFID) tag? - Dis

guineanscarletΗλεκτρονική - Συσκευές

27 Νοε 2013 (πριν από 3 χρόνια και 9 μήνες)

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What is a
R
adio
-
F
requency
Id
entification (RFID) tag?

Chip (IC)


Antenna


In‏terms‏of‏appearance…


RFID devices take many forms

What is a Smart Label ?

A paper label

with RFID inside

an antenna,


printed, etched

or stamped ...

… on a substrate


e.g. a plastic

foil ...

… and a chip

attached to it

“Smart‏label”‏RFID‏tag


Passive device


receives power from reader


Range of up to several meters


Simply calls out (unique) name and static data



“74AB8”

“5F8KJ3”

“Evian bottle

#949837428”

Capabilities‏of‏“smart‏label”‏RFID‏tag


Little memory


Static
96
-
bit+ identifier in current ultra
-
cheap tags


Hundreds of bits soon


Little computational power


Several thousand gates (mostly for basic functionality)



No

real cryptographic functions possible


Pricing pressure may keep it this way for a while, i.e.,
Moore’s‏Law‏will‏have‏delayed‏impact



Use of RF Technology

Airline

Baggage

Tags

Buildin
g

Access

Animal

Trackin
g

Ticketing

Asset

Tracking

Public

Transport

Secure

Network Access

For E
-
business

& Online
Services

Rental

&

Libraries

Use of RF Technology

Parcel


Services

Mobile

Communications

Banking

&

Paymen
t

Vehicle
Access

& Security

Road


Toll

Supply

Chain

Management

“Tree
-
based”‏Technique‏
suggested by Molnar and
Wagner named CR/MW


Challenge
-
response protokol



Tampering with one tag



The attack consists of three phases:


1. The attacker has one tag
T
0

(e.g., her own) she can tamper
with and thus obtain its complete secret. When the number of
tags in the system is large, this does not significantly affect the
results.


2. She then chooses a target tag
T
. She can query it as much
as she wants but she cannot tamper with it.


3. Given two tags
T
1

and
T
2

such that T={
T
1,

T
2
} that
,
we say
that the attacker succeeds if she definitely knows which of
T
1
and
T
2

is
T
.






We consider a given level
i
where s
i
1

and s
i
2

are in the
same subtree. Four cases must be considered:








Ohkubo, Suzuki, and Kinoshita’s Protocol






a numerical comparison of CR, CR/MW, OSK, and
OSK/AO