Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On $2$-parent-identifying set systems of block size $4$   Parent-identifying set system is a kind of combinatorial structures with
applications to broadcast encryption. In this paper we investigate the maximum
number of blocks $I_2(n,4)$ in a $2$-parent-identifying set system with ground
set size $n$ and block size $4$. The previous best known lower bound states
that $I_2(n,4)=\Omega(n^{4/3+o(1)})$. We improve this lower bound by showing
that $I_2(n,4)= \Omega(n^{3/2-o(1)})$ using techniques in additive number
theory.

4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con