The literature of cryptography has a curious history. Secrecy, of course, has always played a central
role, but until the First World War, important developments appeared in print in a more or less
timely fashion and the field moved forward in much the same way as other specialized disciplines.
As late as 1918, one of the most influential cryptanalytic papers of the twentieth century, William F.
Friedman’s monograph The Index of Coincidence and Its Applications in Cryptography, appeared as
a research report of the private Riverbank Laboratories [577]. And this, despite the fact that the work
had been done as part of the war effort. In the same year Edward H. Hebern of Oakland, California
filed the first patent for a rotor machine [710], the device destined to be a mainstay of military
cryptography for nearly 50 years.
標(biāo)簽：
cryptography
literature
has
Secrecy
上傳時間：
2016-12-08
上傳用戶：fxf126@126.com
Abstract—In the future communication applications, users
may obtain their messages that have different importance levels
distributively from several available sources, such as distributed
storage or even devices belonging to other users. This
scenario is the best modeled by the multilevel diversity coding
systems (MDCS). To achieve perfect (information-theoretic)
Secrecy against wiretap channels, this paper investigates the
fundamental limits on the secure rate region of the asymmetric
MDCS (AMDCS), which include the symmetric case as a special
case. Threshold perfect Secrecy is added to the AMDCS model.
The eavesdropper may have access to any one but not more than
one subset of the channels but know nothing about the sources,
as long as the size of the subset is not above the security level.
The question of whether superposition (source separation) coding
is optimal for such an AMDCS with threshold perfect Secrecy
is answered. A class of secure AMDCS (S-AMDCS) with an
arbitrary number of encoders is solved, and it is shown that linear
codes are optimal for this class of instances. However, in contrast
with the secure symmetric MDCS, superposition is shown to
be not optimal for S-AMDCS in general. In addition, necessary
conditions on the existence of a Secrecy key are determined as a
design guideline.
標(biāo)簽：
Fundamental
Limits
Secure
Class
on
of
上傳時間：
2020-01-04
上傳用戶：kddlas
