30,621 research outputs found
An Epitome of Multi Secret Sharing Schemes for General Access Structure
Secret sharing schemes are widely used now a days in various applications,
which need more security, trust and reliability. In secret sharing scheme, the
secret is divided among the participants and only authorized set of
participants can recover the secret by combining their shares. The authorized
set of participants are called access structure of the scheme. In Multi-Secret
Sharing Scheme (MSSS), k different secrets are distributed among the
participants, each one according to an access structure. Multi-secret sharing
schemes have been studied extensively by the cryptographic community. Number of
schemes are proposed for the threshold multi-secret sharing and multi-secret
sharing according to generalized access structure with various features. In
this survey we explore the important constructions of multi-secret sharing for
the generalized access structure with their merits and demerits. The features
like whether shares can be reused, participants can be enrolled or dis-enrolled
efficiently, whether shares have to modified in the renewal phase etc., are
considered for the evaluation
A Generalized Ideal Secret Sharing Scheme
Sharing a secret efficiently amongst a group of
participants is not easy since there is always an adversary /
eavesdropper trying to retrieve the secret. In secret sharing
schemes, every participant is given a unique share. When the
desired group of participants come together and provide their
shares, the secret is obtained. For other combinations of shares,
a garbage value is returned. A threshold secret sharing scheme
was proposed by Shamir and Blakeley independently. In this
(n,t) threshold secret sharing scheme, the secret can be obtained
when at least t out of n participants contribute their shares.
This paper proposes a novel algorithm to reveal the secret only
to the subsets of participants belonging to the access structure.
This scheme implements totally generalized ideal secret sharing.
Unlike threshold secret sharing schemes, this scheme reveals
the secret only to the authorized sets of participants, not any
arbitrary set of users with cardinality more than or equal to t.
Since any access structure can be realized with this scheme, this
scheme can be exploited to implement various access priorities
and access control mechanisms. A major advantage of this
scheme over the existing ones is that the shares being distributed
to the participants is totally independent of the secret being
shared. Hence, no restrictions are imposed on the scheme and it
finds a wider use in real world applications
Secret Sharing for Generic Access Structures
Sharing a secret efficiently amongst a group of participants is not easy since there is always an adversary / eavesdropper trying to retrieve the secret. In secret sharing schemes, every participant is given a unique share. When the desired group of participants come together and provide their shares, the secret is obtained. For other combinations of shares, a garbage value is returned. A threshold secret sharing scheme was proposed by Shamir and Blakeley independently. In this (n,t) threshold secret sharing scheme, the secret can be obtained when at least out of participants contribute their shares. This paper proposes a novel algorithm to reveal the secret only to the subsets of participants belonging to the access structure. This scheme implements totally generalized ideal secret sharing. Unlike threshold secret sharing schemes, this scheme reveals the secret only to the authorized sets of participants, not any arbitrary set of users with cardinality more than or equal to . Since any access structure can be realized with this scheme, this scheme can be exploited to implement various access priorities and access control mechanisms. A major advantage of this scheme over the existing ones is that the shares being distributed to the participants is totally independent of the secret being shared. Hence, no restrictions are imposed on the scheme and it finds a wider use in real world applications
Ideal Tightly Couple (t,m,n) Secret Sharing
As a fundamental cryptographic tool, (t,n)-threshold secret sharing
((t,n)-SS) divides a secret among n shareholders and requires at least t,
(t<=n), of them to reconstruct the secret. Ideal (t,n)-SSs are most desirable
in security and efficiency among basic (t,n)-SSs. However, an adversary, even
without any valid share, may mount Illegal Participant (IP) attack or
t/2-Private Channel Cracking (t/2-PCC) attack to obtain the secret in most
(t,n)-SSs.To secure ideal (t,n)-SSs against the 2 attacks, 1) the paper
introduces the notion of Ideal Tightly cOupled (t,m,n) Secret Sharing (or
(t,m,n)-ITOSS ) to thwart IP attack without Verifiable SS; (t,m,n)-ITOSS binds
all m, (m>=t), participants into a tightly coupled group and requires all
participants to be legal shareholders before recovering the secret. 2) As an
example, the paper presents a polynomial-based (t,m,n)-ITOSS scheme, in which
the proposed k-round Random Number Selection (RNS) guarantees that adversaries
have to crack at least symmetrical private channels among participants before
obtaining the secret. Therefore, k-round RNS enhances the robustness of
(t,m,n)-ITOSS against t/2-PCC attack to the utmost. 3) The paper finally
presents a generalized method of converting an ideal (t,n)-SS into a
(t,m,n)-ITOSS, which helps an ideal (t,n)-SS substantially improve the
robustness against the above 2 attacks
Hierarchical quantum communication
A general approach to study the hierarchical quantum information splitting
(HQIS) is proposed and the same is used to systematically investigate the
possibility of realizing HQIS using different classes of 4-qubit entangled
states that are not connected by SLOCC. Explicit examples of HQIS using 4-qubit
cluster state and 4-qubit |\Omega> state are provided. Further, the proposed
HQIS scheme is generalized to introduce two new aspects of hierarchical quantum
communication. To be precise, schemes of probabilistic hierarchical quantum
information splitting and hierarchical quantum secret sharing are obtained by
modifying the proposed HQIS scheme. A number of practical situations where
hierarchical quantum communication would be of use are also presented.Comment: 14 pages, 6 tables, no figur
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