Abstract
With two \mathbb{Z} -linear independence endomorphisms \Phi and \Psi satisfying \Phi^{2}+r\Phi+s=0 and \Psi^{2}-t_{\Psi}\Psi+n_{\Psi}=0 , we construct general 4-GLV lattice reduction algorithms with \mathbb{Z}[\Psi\vert principal maximal orders of imaginary quadratic fields \mathbb{Q}(\sqrt{-d}) . The algorithms can be used to calculate short bases for 4-GLV decompositions on elliptic curves (or Jacobians of genus 2 curves). Our algorithms have a theoretic upper bound of output Cn^{1/4} , where \begin{align*} C=\begin{cases} {\frac{4+2\sqrt{d+1}}{3-d}} (\sqrt{1+\vert r\vert +\vert s\vert }),\ &\text{if}\ \mathbb{Z}[\Psi]=\mathbb{Z}[\frac{1+\sqrt{-d}}{2}],\\ \frac{4\sqrt{d}}{(4\sqrt{d}-(d+1)}(\sqrt{1+\vert r\vert +\vert s\vert }),\ &\text{if}\ \mathbb{Z}[\Psi]=\mathbb{Z}[\frac{1+\sqrt{-d}}{2}].\end{cases}\end{align*} Especially, our algorithms cover the case \mathbb{Z}[\Psi]=\mathbb{Z}[\sqrt{-1}] of Yi et al. (SAC 2017) and the case \mathbb{Z}[\Psi]=\mathbb{Z}[\frac{1+\sqrt{-3}}{2}] of Wang et al. (AMC 2021).