3,190 research outputs found
Extracting secret keys from integrated circuits
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.Includes bibliographical references (p. 117-119).Modern cryptographic protocols are based on the premise that only authorized participants can obtain secret keys and access to information systems. However, various kinds of tampering methods have been devised to extract secret keys from widely fielded conditional access systems such as smartcards and ATMs. As a solution, Arbiter-based Physical Unclonable Functions (PUFs) are proposed. This technique exploits statistical delay variation of wires and transistors across integrated circuits (ICs) in the manufacturing processes to build a secret key unique to each IC. We fabricated Arbiter-based PUFs in custom silicon and investigated the identification based PUFs in custom silicon and investigated the identification capability, reliability, and security of this scheme. Experimental results and theoretical studies show that a sufficient amount of variation exists across ICs. This variation enables each IC to be identified securely and reliably over a practical range of environmental variations such as temperature and power supply voltage. Thus, arbiter-based PUFs are well-suited to build key-cards and membership cards that must be resistant to cloning attacks.by Daihyun Lim.S.M
Trojans in Early Design Steps—An Emerging Threat
Hardware Trojans inserted by malicious foundries
during integrated circuit manufacturing have received substantial
attention in recent years. In this paper, we focus on a different
type of hardware Trojan threats: attacks in the early steps of
design process. We show that third-party intellectual property
cores and CAD tools constitute realistic attack surfaces and that
even system specification can be targeted by adversaries. We
discuss the devastating damage potential of such attacks, the
applicable countermeasures against them and their deficiencies
Reversible Data Hiding in Encrypted Images Using MSBs Integration and Histogram Modification
This paper presents a reversible data hiding in encrypted image that employs
based notions of the RDH in plain-image schemes including histogram
modification and prediction-error computation. In the proposed method, original
image may be encrypted by desire encryption algorithm. Most significant bit
(MSB) of encrypted pixels are integrated to vacate room for embedding data
bits. Integrated ones will be more resistant against failure of reconstruction
if they are modified for embedding data bits. At the recipient, we employ
chess-board predictor for lossless reconstruction of the original image by the
aim of prediction-error analysis. Comparing to existent RDHEI algorithms, not
only we propose a separable method to extract data bits, but also content-owner
may attain a perfect reconstruction of the original image without having data
hider key. Experimental results confirm that the proposed algorithm outperforms
state of the art ones
Barrel Shifter Physical Unclonable Function Based Encryption
Physical Unclonable Functions (PUFs) are circuits designed to extract
physical randomness from the underlying circuit. This randomness depends on the
manufacturing process. It differs for each device enabling chip-level
authentication and key generation applications. We present a protocol utilizing
a PUF for secure data transmission. Parties each have a PUF used for encryption
and decryption; this is facilitated by constraining the PUF to be commutative.
This framework is evaluated with a primitive permutation network - a barrel
shifter. Physical randomness is derived from the delay of different shift
paths. Barrel shifter (BS) PUF captures the delay of different shift paths.
This delay is entangled with message bits before they are sent across an
insecure channel. BS-PUF is implemented using transmission gates; their
characteristics ensure same-chip reproducibility, a necessary property of PUFs.
Post-layout simulations of a common centroid layout 8-level barrel shifter in
0.13 {\mu}m technology assess uniqueness, stability and randomness properties.
BS-PUFs pass all selected NIST statistical randomness tests. Stability similar
to Ring Oscillator (RO) PUFs under environment variation is shown. Logistic
regression of 100,000 plaintext-ciphertext pairs (PCPs) failed to successfully
model BS- PUF behavior
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