Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: SeF: A Secure Fountain Architecture for Slashing Storage Costs in
  Blockchains
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin