# Tag Info

## Hot answers tagged attribute-based-encry

3

This is a bilinear pairing used in cryptography. More precisely it's an evaluation of an appropriate pairing friendly elliptic curve equation.(1,2,3,4,5)

2

If you need something that already exists, have a look at the advanced Crypto software collection and specifically cpabe — which implements ciphertext-policy attribute-based encryption scheme that uses C and PBC library for pairings.

1

I think you have a lack of knowledge on pairings and finite fields. Your definition of the pairing $e(X,Y)=g^{XY} \bmod p$ is not correct. A pairing is defined as a map $e : \mathbb{G}_1 \times \mathbb{G}_2 \to \mathbb{G}_T$ with the property \begin{align}\text{for all }g_1 \in \mathbb{G}_1 \text{ and } g_2 \in \mathbb{G}_2: e(g_1^a,g_2^b) = ...

1

My understanding of this is as follows: Monotonic access structure: if $\mathbb{A}$ is a set of attributes satisfying an access structure $T$, then any $\mathbb{A}'$ such that $\mathbb{A} \subset \mathbb{A}'$ also satisfies $T$. For example, consider $T = A \cap B$, then both $\mathbb{A}=\{A,B\}$ and $\mathbb{A}'=\{A,B,C\}$ satisfy $T$. Non-monotonic ...

1

Simply speaking, if any superset of the set satisfying the access structure satisfies the access structure, we call the structure monotonic. Let $\{1,2,...,n\}$ be a set of indices. An access structure is a collection $\mathbb{A}$ of non-empty subsets of $\{1,2,3,...,n\}$. We say a collection (or an access structure) $\mathbb{A} \subseteq 2^{\{1,2,...,n\}}$ ...

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