New Bounds on the Distance Distribution of Extended Goppa Codes

AbstractWe derive new estimates for the error term in the binomial approximation to the distance distribution of extended Goppa codes. This is an improvement on the earlier bounds by Vladuts and Skorobogatov, and Levy and Litsyn

The problem with the SURF scheme

There is a serious problem with one of the assumptions made in the security proof of the SURF scheme. This problem turns out to be easy in the regime of parameters needed for the SURF scheme to work. We give afterwards the old version of the paper for the reader's convenience.Comment: Warning : we found a serious problem in the security proof of the SURF scheme. We explain this problem here and give the old version of the paper afterward