Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Problems of Existing Unconditional Security Proofs in Quantum Key
  Distribution   It is repeatedly and persistently claimed in the literature that a specific
trace criterion $d$ would guarantee universal composition security in quantum
cryptography. Currently that is the sole basis of unconditional security claim
in quantum key distribution. In this paper, it is shown that just security
against known-plaintext attacks when the generated key is used in direct
encryption is not provided by $d$. The problem is directly connected with
several general problems in the existing unconditional security proofs in
quantum key distribution. A number of issues will be clarified concerning the
nature of true security, privacy amplification, key generation rate and the
mathematical approach needed for their determination in concrete protocols.

4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics