Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Some Applications of Directed Signature Scheme   Directed signature scheme is applicable when the signed message contains
information sensitive to the receiver, because only receiver can directly
verify the signature and that he/she can prove its validity to any third party,
whenever necessary. This paper presents two applications of directed signature
scheme. (i) Directed &#8211;Delegated Signature Scheme. This scheme combines
the idea of proxy signatures with directed signature scheme. (ii) Allocation of
registration number. This scheme proposes a registration scheme in which the
registration number cannot be forged and misused.

15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys