1,029 research outputs found
Practical Preimages for Maraca
We show a practical preimage attack on the cryptographic hash function Maraca, which was submitted as a candidate to the NIST SHA-3 competition. Our attack has been verified experimentially
SCM : Secure Code Memory Architecture
An increasing number of applications implemented on a SoC (System-on-chip) require security features. This work addresses the issue of protecting the integrity of code and read-only data that is stored in memory. To this end, we propose a new architecture called SCM, which works as a standalone IP core in a SoC. To the best of our knowledge, there exist no architectural elements similar to SCM that offer the same strict security guarantees while, at the same time, not requiring any modifications to other IP cores in its SoC design. In addition, SCM has the flexibility to select the parts of the software to be protected, which eases the integration of our solution with existing software. The evaluation of SCM was done on the Zynq platform which features an ARM processor and an FPGA. The design was evaluated by executing a number of different benchmarks from memory protected by SCM, and we found that it introduces minimal overhead to the system
On Proactive Verifiable Secret Sharing Schemes
The paper has been presented at the International Conference Pioneers of Bulgarian
Mathematics, Dedicated to Nikola Obreshkoff and Lubomir Tschakaloff , Sofia, July, 2006.
The material in this paper was presented in part at the 11th Workshop on Selected Areas in Cryptography (SAC) 2004This paper investigates the security of Proactive Secret Sharing
Schemes. We first consider the approach of using commitment to 0 in the
renewal phase in order to refresh the player's shares and we present two types
of attacks in the information theoretic case. Then we prove the conditions
for the security of such a proactive scheme. Proactivity can be added also
using re-sharing instead of commitment to 0. We investigate this alternative
approach too and describe two protocols. We also show that both techniques
are not secure against a mobile adversary.
To summarize we generalize the existing threshold protocols to protocols
for general access structure. Besides this, we propose attacks against the
existing proactive verifiable secret sharing schemes, and give modifications
of the schemes that resist these attacks
On Distributed Oblivious Transfer
The paper has been presented at the International Conference Pioneers of Bulgarian Mathematics, Dedicated to Nikola Obreshkoff and Lubomir Tschakaloff , Sofia, July, 2006. The material in this paper was presented in part at INDOCRYPT 2002This paper is about unconditionally secure distributed protocols
for oblivious transfer, as proposed by Naor and Pinkas and generalized by
Blundo et al. In this setting a Sender has ζ secrets and a Receiver is
interested in one of them. The Sender distributes the information about
the secrets to n servers, and a Receiver must contact a threshold of the
servers in order to compute the secret. We present a non-existence result
and a lower bound for the existence of one-round, threshold, distributed
oblivious transfer protocols, generalizing the results of Blundo et al. A
threshold based construction implementing 1-out-of-ζ distributed oblivious
transfer achieving this lower bound is described. A condition for existence
of distributed oblivious transfer schemes based on general access structures
is proven. We also present a general access structure protocol implementing
1-out-of-ζ distributed oblivious transfer
09031 Abstracts Collection -- Symmetric Cryptography
From 11.01.09 to 16.01.09, the Seminar 09031 in
``Symmetric Cryptography \u27\u27 was held
in Schloss Dagstuhl~--~Leibniz Center for Informatics.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
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