Explicit 2-power torsion of genus 2 curves over finite fields

We give an efficient explicit algorithm to find the structure and generators of the maximal 2-subgroup of the Jacobian of a genus 2 curve over a finite field of odd characteristic. We use the 2-torsion points as seeds to successively perform a chain of halvings to ind divisors of increasing 2-power...

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Detalles Bibliográficos
Autores: Miret, Josep M. (Josep Maria), Pujolàs Boix, Jordi, Rio, Anna
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2010
País:España
Institución:Universitat de Lleida (UdL)
Repositorio:Repositori Obert UdL
OAI Identifier:oai:repositori.udl.cat:10459.1/469529
Acceso en línea:https://doi.org/10.3934/AMC.2010.4.155
https://hdl.handle.net/10459.1/469529
Access Level:acceso abierto
Palabra clave:Finite fields
Genus 2 curves
Jacobian
Descripción
Sumario:We give an efficient explicit algorithm to find the structure and generators of the maximal 2-subgroup of the Jacobian of a genus 2 curve over a finite field of odd characteristic. We use the 2-torsion points as seeds to successively perform a chain of halvings to ind divisors of increasing 2-power order. The halving loop requires a solution to certain degree 16 polynomials over the base ield, and the termination of the algorithm is based on the description of the graph structure of the maximal 2-subgroup. The structure of our algorithm is the natural extension of the even characteristic case. © 2010 AIMS-SDU.