A User Centric Security Model for Tamper-Resistant Devices

A.1 Protocol Notation and Terminology
A.1 Protocol Notation and Terminology
The notation used to describe protocols in this appendix is as below.
Table A.1: Protocol notation and terminology
Notation Description
SC Denotes a smart card (in context of this thesis).
T T P Denotes the trusted third party.
SP Denotes an SP (in context of this thesis).
X i Indicates the identity of an entity X.
N X a random number generated by entity X.
g X Die-Hellman exponential generated by an entity X.
h(Z) The result of applying a hash algorithm (e.g. SHA-256) on data Z.
k X−Y Encryption key shared between entities X and Y.
mk X−Y MAC key for symmetric algorithms shared between entities X and Y.
B X Private decryption key associated with an entity X.
V X Public encryption key associated with an entity X.
f K (Z) Result of applying MAC algorithm on data Z with key K.
zK X (Z) Result of encrypting data Z using public key algorithm (e.g. RSA) with
key K X .
e K (Z) Result of encrypting data Z using symmetric key algorithm (e.g. AES)
with key K.
Sign X (Z) Is the signature on data Z with the signature key belonging to the entity
X using a signature algorithm like DSA or based on the RSA function.
CertS X Is the certicate for the signature key belonging to the entity X.
CertE X Certicate for the public key belonging to the entity X.
X → Y : C Entity X sends a message to entity Y with contents C.
X||Y Represents the concatenation of data items X and Y.
A.2 Station-to-Station (STS) Protocol
The STS protocol provides a three-pass mutual entity authentication and mutual explicit
key authentication to two communicating parties [174]. The protocol described in this
section is from the Meneze et al. [146], which includes an encrypted certicate from the
smart card to provide privacy preservation.
STS-1. SC → SP : g SC
SP : k SC−SP = (g SC ) SP
The smart card (SC) initiates the STS protocol by generating a Die-Hellman exponential
and communicating it to the server (SP). The SP will generate a shared secret by k SC−SP
from the shared public key of the SC (i.e. g SC ) with the private key of the SP (i.e. N S P).
STS-2. SP → SC : g SP ||e kSC−SP (Sign SP (g SP ||g SC ))||CertS SP
SC : k SC−SP = (g SP ) SC
In response, the SP generates a public key (e.g. g SP ) along with encrypting the signature
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