Error message
- Deprecated function: TYPO3\PharStreamWrapper\Manager::initialize(): Implicitly marking parameter $resolver as nullable is deprecated, the explicit nullable type must be used instead in include_once() (line 19 of includes/file.phar.inc).
- Deprecated function: TYPO3\PharStreamWrapper\Manager::initialize(): Implicitly marking parameter $collection as nullable is deprecated, the explicit nullable type must be used instead in include_once() (line 19 of includes/file.phar.inc).
- Deprecated function: TYPO3\PharStreamWrapper\Manager::__construct(): Implicitly marking parameter $resolver as nullable is deprecated, the explicit nullable type must be used instead in include_once() (line 19 of includes/file.phar.inc).
- Deprecated function: TYPO3\PharStreamWrapper\Manager::__construct(): Implicitly marking parameter $collection as nullable is deprecated, the explicit nullable type must be used instead in include_once() (line 19 of includes/file.phar.inc).
- Deprecated function: UpdateQuery::expression(): Implicitly marking parameter $arguments as nullable is deprecated, the explicit nullable type must be used instead in require_once() (line 1884 of includes/database/database.inc).
- Deprecated function: MergeQuery::expression(): Implicitly marking parameter $arguments as nullable is deprecated, the explicit nullable type must be used instead in require_once() (line 1884 of includes/database/database.inc).
Oblivious transfer (OT) is a cryptographic
primitive between two parties, in the following called Alice and Bob.
OT can be used as a building block for any arbitrary multiparty
computation protocol (including, e.g.,
bit
commitment).
It exists various versions of OT primitives, whose
functionality of some of them is explained in the following.
- Rabin OT: Alice chooses as input one bit b. Then, with probability 1/2, Bob
gets the bit b, and nothing
otherwise.
- 1-out-of-2 OT: Alice chooses as input two bits
b0 and b1. Bob chooses a
selection bit c and gets as
output the bit bc.
It can be shown that these two versions of OT can be reduced
to each other. Moreover, one can define similar functionalities for
strings (instead of bits).
A protocol for realizing OT is said to be secure if
none of the two parties learns any information she is not supposed to
learn according to the above description (e.g., in 1-out-of-2
OT, Alice should be unable to learn the selection bit c chosen
by Bob.)
Classically, there are only computationally secure OT
protocols. In fact, it can be shown that even with the help of quantum
mechanics, fully secure OT cannot be realized, unless
additional assumptions are made.
Recently, Damgaard, Fehr, Salvail, and Schaffner came up with a
quantum protocol for realizing OT (and bit commitment) which is
secure under the sole assumption that the adversary cannot store more
than a certain number of qubits.
Category:Quantum
Cryptography
Last modified:
Monday, October 26, 2015 - 17:56
