28,543 research outputs found
Optimal Multiple Assignments with (m,m)-Scheme for General Access Structures
Given the number n of the participants, one can solve an integer programming on 2^n variables to construct an optimal multiple assignment with threshold schemes for general access structure. In this paper, we focus on finding optimal multiple assignments with (m,m)-schemes. We prove that most of the variables in the corresponding integer programming take the value of 0, while the remaining variables take the values of either 0 or 1. We also show that given a complete access structure, an optimal scheme may be obtaineddirectly from the scheme by Ito, Saito, and Nishizeki (Secret
sharing scheme realizeing any access structure, in Globecom 1987)
Designing Robust LMCA-based Threshold Secret Sharing Scheme for Digital Images Using Multiple Configurations Assignment
In this paper, we present a new (t,n)-threshold secret images sharing scheme based on linear memory cellular automata (LMCA). While all existing LMCA-based sharing scheme are not robust, the proposed one provides full robustness property. Precisely, any subset of t participants can collude to recover the shared secret, in contrast to existing LMCA-based schemes when this is possible only for participants having consecutive shares. To achieve robustness, produced shares are constructed using subsets of different LMCA’s configurations instead of using single ones. The subsets are defined according to an assignments matrix that is generated using a specific heuristic. The proposed scheme is shown to be robust, and its security is experimentally evaluated with respect to the problem of secret color image sharing. Obtained results illustrate the secrecy of the produced shares, while comparison gives an accurate evaluation with respect to existing schemes
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
Callisto: a cryptographic approach to detecting serial perpetrators of sexual misconduct
Sexual misconduct is prevalent in workplace and education settings
but stigma and risk of further damage deter many victims from
seeking justice. Callisto, a non-profit that has created an online sexual assault reporting platform for college campuses, is expanding its
work to combat sexual assault and harassment in other industries.
In this new product, users will be invited to an online "matching
escrow" that will detect repeat perpetrators and create pathways
to support for victims. Users submit encrypted data about their
perpetrator, and this data can only be decrypted by the Callisto
Options Counselor (a lawyer), when another user enters the identity of the same perpetrator. If the perpetrator identities match,
both users will be put in touch independently with the Options
Counselor, who will connect them to each other (if appropriate) and
help them determine their best path towards justice. The client relationships with the Options Counselors are structured so that any
client-counselor communications would be privileged. A combination of client-side encryption, encrypted communication channels,
oblivious pseudo-random functions, key federation, and Shamir
Secret Sharing keep data confidential in transit, at rest, and during
the matching process with the guarantee that only the lawyer ever
has access to user submitted data, and even then only when a match
is identified.Accepted manuscrip
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