Data Sheet

Chips and readers- USERíS GUIDE
UG 11
Version 1.0
MANAGING THE SECURITY
INSIDE chips security is based on secret keys that protect and authentify the chip con-
tent.
On one hand, keys are stored in the chip. On the other hand, coupler includes a security
module in which are stored the application keys.
Security is based on checking that keys are the same in the chip and in the coupler.
First paragraph explains on what is based our security and what it is for :
# Authentication
# Signature
# Diversified keys
The following paragraphs explain how to :
# load the key into the coupler / SAM
# select and / or authenticate a chip with a given key
INSIDE CHIPS SECURITY
Security consists in protecting memory access and e-purse use by secret keys. User
will be able to modify card content only if the coupler contains same secret keys as
PICO chip.
Security is checked several times :
##
##
# Authentication : Just after having selected the chip user has to perform an
authentication before being able to access any memory data.
##
##
# Signature : for any memory modification the chip user has to send a signature
calculated as a function of sent data, secret keys and chip serial number. Thus it
is impossible to modify the chip content without knowing the application keys.
In each security calculation, a diversified key is being used, based on the chip serial
number and the application key.
All security calculations are automatically manage by INSIDEís couplers.
Key diversification
To ensure a reliable security, every security operation (authentication, signature
calculation) is based on diversified key value.
The diversified key is an 8 bytes result of calculation including chip serial number and
key value.
Thus, 2 chips using same keys contain different diversified key values. This ensures
that it is not possible to repeat some sequence registered on one card on another card.
Secret Key
Chip serial number
Diversified Key
+
x
%
DES
Key
fortification
algorythm
Security
control e-purse
(stored value) manage-
ment
INSIDE
security protects
memory from REA-
DING and/or WRITING.
Key diversifi-
cation implies that
each security
calculation is different
for each card
Security is
based on :
- key diversification
- authentication
-signature