@string{brics = "{BRICS}"}
@string{daimi = "Department of Computer Science, University of Aarhus"}
@string{iesd = "Department of Computer Science, Institute
of Electronic Systems, Aalborg University"}
@string{rs = "Research Series"}
@string{ns = "Notes Series"}
@string{ls = "Lecture Series"}
@string{ds = "Dissertation Series"}
TechReport{BRICS-DS-05-,
author = "",
title = "",
institution = brics,
year = 2005,
OPTkey = "",
type = ds,
number = "DS-05-",
address = daimi,
OPTmonth = "",
note = "PhD thesis",
comment = "Defence: , 2005",
abstract = "",
OPTlinkhtmlabs = "",
OPTlinkps = "",
OPTlinkpdf = ""
}
@techreport{BRICS-DS-05-1,
author = "Morozov, Kirill",
title = "On Cryptographic Primitives Based on Noisy Channels",
institution = brics,
year = 2005,
type = ds,
number = "DS-05-1",
address = daimi,
month = mar,
note = "PhD thesis. xii+102~pp",
comment = "Defence: March~11, 2005",
abstract = "The primitives of Oblivious Transfer (OT) and Bit
Commitment (BC) are fundamental in the cryptographic
protocol design. OT is a complete primitive for
secure two-party computation, while zero-knowledge
proofs are based on BC. In this work, the
implementations of OT and BC with unconditional
security for both parties are considered. The
security of these protocols does not depend on
unproven intractability assumptions. Instead, we
assume that the players are connected by noisy
channels. This is a very natural assumption since
noise is inherently present in the real
communication channels.\bibpar We present and prove
secure a protocol for OT based on a Discrete
Memoryless Channel (DMC) with probability transition
matrix of a general form. The protocol is secure for
any non-trivial DMC. Some generalisations to this
protocol for the particular case of Binary Symmetric
Channel (BSC) are presented and their asymptotic
behaviour is analysed.\bibpar The security of OT and
BC based on BSC is also analysed in the
non-asymptotic case. We derive relations for the
failure probabilities depending on the number of
channel uses establishing trade-offs between their
communication complexity on the one hand and the
security on the other hand.\bibpar We consider a
modification to the Universally Composable (UC)
framework for the case of unconditional two-party
protocols. We argue that this modification is valid
hereby preparing a ground for our results concerning
OT based on Unfair Noisy Channels (UNC).\bibpar In
contrast to the noise models mentioned above, a
corrupted party is given a partial control over the
randomness introduced by UNC. We introduce a generic
``compiler'' which transforms any protocol
implementing OT from a passive version of UNC and
secure against passive cheating into a protocol that
uses UNC for communications and builds an OT secure
against active cheating. We exploit this result and
a new technique for transforming between the weaker
versions of OT in order to obtain new possibility
results for OT based on UNC",
linkhtmlabs = "",
linkps = "",
linkpdf = ""
}