If I have an encrypted value $Enc(x)$ with Paillier cryptosystem, is it feasible to compute an encryption form of $\ln(x)$ or its approximation using homomorphic properties? The input $x$ is always positive. The $\ln$ function satisfies $\ln(1)=0$ and the derivative of $\ln$ function is $1/x$. Or if I want to compute its approximation, what other information do I need?
closed as unclear what you're asking by kelalaka, AleksanderRas, Maeher, Squeamish Ossifrage, Maarten Bodewes♦ Sep 21 at 21:48
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