Eléments sur les codes de Goppa en relation avec le protocole de McEliece

Pierre Loidreau

BP 105
78153 Le Chesnay Cedex, France

Rapport de DEA,
Ecole Polytechnique, 1997


The distribution of the dimension of the Hull of binary Goppa codes is different from the distribution of the Hull of random codes. The structure of this distribution depends very much on the structure of the support field. However binary Goppa codes with large Hulls (dimension greater than 15) are generated by particular polynomials. It is thus possible to apply the Support Splitting Algorithm to recover their automorphism group.