Paper 2020/1035

Evolving Secret Sharing with Essential Participants

Jyotirmoy Pramanik and Avishek Adhikari


Komargodski introduced {\em Evolving Secret Sharing} which allows an imaprtial participant, called \emph{dealer}, to share a secret among unbounded number of participants over any given access structure. In their construction for evolving secret sharing over general access structure, the size of share of the $i^{th}$ participant happens to be exponential $(\mathcal{O}(2^{i-1}))$. They also provided constructions for $(k,\infty)$ threshold secret sharing. We consider the problem of evolving secret sharing with $t$ essential participants, namely, over $t$-$(k,\infty)$ access structure, a generalization of $(k,\infty)$ secret sharing $(t=0)$. We further generalize this access structure to a possible case of unbounded number of essential participants and provide a construction for secret sharing on it. Both the constructions are information theoretically secure and reduce the share size of the construction due to Komargodski over general access structure, exponentially. Moreover, the essential participants receive ideal (and hence, optimal) shares in the first construction.

Available format(s)
Cryptographic protocols
Publication info
Published elsewhere. Minor revision. COMSYS 2020 (to appear)
Evolving Access StructureSecret SharingEssential ParticipantsInformation Theoretic
Contact author(s)
jyotirmoy pramanik2 @ gmail com
avishek adh @ gmail com
2020-08-27: received
Short URL
Creative Commons Attribution


      author = {Jyotirmoy Pramanik and Avishek Adhikari},
      title = {Evolving Secret Sharing with Essential Participants},
      howpublished = {Cryptology ePrint Archive, Paper 2020/1035},
      year = {2020},
      note = {\url{}},
      url = {}
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