Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonsignaling quantum random access code boxes   A well known cryptographic primitive is so called random access code. Namely,
Alice is to send to Bob one of two bits, so that Bob has the choice which bit
he wants to learn about. However at any time Alice should not learn Bob's
choice, and Bob should learn only the bit of his choice. The task is impossible
to accomplish by means of either classical or quantum communication. On the
other hand, a concept of correlations stronger than quantum ones, exhibited by
so called Popescu- Rohrlich box, was introduced and widely studied. In
particular, it is known that Popescu-Rohrlich box enables simulation of the
random access code with the support of one bit of communication. Here, we
propose a quantum analogue of this phenomenon. Namely, we define an analogue of
a random access code, where instead of classical bits, one encodes qubits. We
provide a quantum non-signaling box that if supported with two classical bits,
allows to simulate a quantum version of random access code. We point out that
two bits are necessary. We also show that a quantum random access code cannot
be fully quantum: when Bob inputs superposition of two choices, the output will
be in a mixed state rather than in a superposition of required states.

22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat