361 research outputs found
Secure and {\sl Practical} Identity-Based Encryption
In this paper, we present a variant of Waters' Identity-Based Encryption
scheme with a much smaller public-key size (only a few kilobytes). We show that
this variant is semantically secure against passive adversaries in the standard
model.\smallskip
In essence, the new scheme divides Waters' public key size by a factor
at the cost of (negligibly) reducing security by bits. Therefore, our
construction settles an open question asked by Waters and constitutes the first
fully secure {\sl practical} Identity-Based Encryption schem
Physical Simulation of Inarticulate Robots
In this note we study the structure and the behavior of inarticulate robots.
We introduce a robot that moves by successive revolvings. The robot's structure
is analyzed, simulated and discussed in detail
Information Security Theory and Practice: Securing the Internet of Things: 8th IFIP WG 11.2 InternationalWorkshop, WISTP 2014, Heraklion, Crete, Greece, June 30-July 2, 2014
International audienceBook Front Matter of LNCS 850
Operand Folding Hardware Multipliers
This paper describes a new accumulate-and-add multiplication algorithm. The
method partitions one of the operands and re-combines the results of
computations done with each of the partitions. The resulting design turns-out
to be both compact and fast.
When the operands' bit-length is 1024, the new algorithm requires only
additions (on average), this is about half the number of additions
required by the classical accumulate-and-add multiplication algorithm
()
The Balkans Continued Fraction
In a previous article we gave a collection of continued fractions involving
Catalan's constant. This paper provides more general formulae governing those
continued fractions. Having distinguished different cases associated to regions
in the plan, we nickname those continued fractions \enquote{The Balkans} as
they divide into areas which are related but still different in nature.
Because we do not provide formal proofs of those machine-constructed formulae
we do not claim them to be theorems. Still, each and every proposed formula was
extensively tested numerically
Divisibility, Smoothness and Cryptographic Applications
This paper deals with products of moderate-size primes, familiarly known as
smooth numbers. Smooth numbers play a crucial role in information theory,
signal processing and cryptography.
We present various properties of smooth numbers relating to their
enumeration, distribution and occurrence in various integer sequences. We then
turn our attention to cryptographic applications in which smooth numbers play a
pivotal role
The Polynomial Composition Problem in (Z/nZ)[X]
Abstract. Let n be an RSA modulus and let P, Q ∈ (Z/nZ)[X]. This paper explores the following problem: Given polynomials Q and Q(P), find polynomial P. We shed light on the connections between the above problem and the RSA problem and derive from it new zero-knowledge protocols suited to smart-card applications. Keywords: Polynomial composition, zero-knowledge protocols, Fiat-Shamir protocol, Guillou-Quisquater protocol, smart cards
Robust Encryption, Extended
Robustness is a notion often tacitly assumed while working with encrypted data. Roughly speaking, it states that a ciphertext cannot be decrypted under different keys. Initially formalized in a public-key context, it has been further extended to key-encapsulation mechanisms, and more recently to pseudorandom functions, message authentication codes and authenticated encryption. In this work, we motivate the importance of establishing similar guarantees for functional encryption schemes, even under adversarially generated keys. Our main security notion is intended to capture the scenario where a ciphertext obtained under a master key (corresponding to Authority 1) is decrypted by functional keys issued under a different master key (Authority 2). Furthermore, we show there exist simple functional encryption schemes where robustness under adversarial key-generation is not achieved. As a secondary and independent result, we formalize robustness for digital signatures – a signature should not verify under multiple keys – and point out that certain signature schemes are not robust when the keys are adversarially generated. We present simple, generic transforms that turn a scheme into a robust one, while maintaining the original scheme’s security. For the case of public-key functional encryption, we look into ciphertext anonymity and provide a transform achieving it
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