11,286 research outputs found
Quantum Circuits for Toom-Cook Multiplication
In this paper, we report efficient quantum circuits for integer
multiplication using Toom-Cook algorithm. By analysing the recursive tree
structure of the algorithm, we obtained a bound on the count of Toffoli gates
and qubits. These bounds are further improved by employing reversible pebble
games through uncomputing the intermediate results. The asymptotic bounds for
different performance metrics of the proposed quantum circuit are superior to
the prior implementations of multiplier circuits using schoolbook and Karatsuba
algorithms
Time- and Space-Efficient Evaluation of Some Hypergeometric Constants
The currently best known algorithms for the numerical evaluation of
hypergeometric constants such as to decimal digits have time
complexity and space complexity of or .
Following work from Cheng, Gergel, Kim and Zima, we present a new algorithm
with the same asymptotic complexity, but more efficient in practice. Our
implementation of this algorithm improves slightly over existing programs for
the computation of , and we announce a new record of 2 billion digits for
Quantum resource estimates for computing elliptic curve discrete logarithms
We give precise quantum resource estimates for Shor's algorithm to compute
discrete logarithms on elliptic curves over prime fields. The estimates are
derived from a simulation of a Toffoli gate network for controlled elliptic
curve point addition, implemented within the framework of the quantum computing
software tool suite LIQ. We determine circuit implementations for
reversible modular arithmetic, including modular addition, multiplication and
inversion, as well as reversible elliptic curve point addition. We conclude
that elliptic curve discrete logarithms on an elliptic curve defined over an
-bit prime field can be computed on a quantum computer with at most qubits using a quantum circuit of at most Toffoli gates. We are able to classically simulate the
Toffoli networks corresponding to the controlled elliptic curve point addition
as the core piece of Shor's algorithm for the NIST standard curves P-192,
P-224, P-256, P-384 and P-521. Our approach allows gate-level comparisons to
recent resource estimates for Shor's factoring algorithm. The results also
support estimates given earlier by Proos and Zalka and indicate that, for
current parameters at comparable classical security levels, the number of
qubits required to tackle elliptic curves is less than for attacking RSA,
suggesting that indeed ECC is an easier target than RSA.Comment: 24 pages, 2 tables, 11 figures. v2: typos fixed and reference added.
ASIACRYPT 201
Faster truncated integer multiplication
We present new algorithms for computing the low n bits or the high n bits of
the product of two n-bit integers. We show that these problems may be solved in
asymptotically 75% of the time required to compute the full 2n-bit product,
assuming that the underlying integer multiplication algorithm relies on
computing cyclic convolutions of real sequences.Comment: 28 page
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