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In the paper about ABE (like this), the access structure is defined as follow:

Let ${P_1,P_2,...,P_n}$ be a set of parties. A collection $A⊆2^{\{P_1,P_2,...,P_n\}}$ is monotone if $∀B,C$: if $B∈A$ and $B⊆C$ then $C∈A$ ...

What is the meaning of this notation: $2^{\{P_1,P_2,...,P_n\}}$? Can you give some example while explaining?

Z. Chen
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1 Answers1

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It is the powerset of all subsets of $\{P_1,\ldots,P_n\}$. Therefore

$$2^{\{P_1,P_2,P_3\}}=\{\{ \},\{P_1\},\{P_2\},\{P_3\},\{P_1,P_2\},\{P_1,P_3\}, \{P_2,P_3\},\{P_1,P_2,P_3\}\} $$ for example.

kodlu
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