I read a cryptography scheme that it include the following operation:
$$c= H(e(g_1,g_n)^t)$$ where H is a hash function. I need to know what the operation $e$ means.
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Sign up to join this communityI read a cryptography scheme that it include the following operation:
$$c= H(e(g_1,g_n)^t)$$ where H is a hash function. I need to know what the operation $e$ means.
It's the pairing function. This bilinear map which takes as input an element from the set $\mathbb{G}\times\hat{\mathbb{G}}$ (in the common case, elliptic curves), and outputs a group element in $\mathbb{G}_T$, the target group.
In the symmetric case (Type 1), because $e$ is bilinear, you can deduce that $$e(g_1, g_n)^t= e(g, g)^{x_1x_nt}$$
with $x_1,x_n$ respectively the discrete logarithms of $g_1, g_n$ in base $g$.
For more details check: https://en.wikipedia.org/wiki/Pairing-based_cryptography