Update README.md

README.md

+Authors : Cyrius NUGIER and Remi ADELIN
+Institute : LAAS-CNRS, INSA Toulouse, Univ Toulouse, FRANCE
+
+This git contains a DH and a KEM implementation of 3 different versions of the Megrelishvili protocol.
+
+1. "phsmat256b" One base version, a priori faster that is not constant-time coded.
+2. "phsmat256t" Constant time version, with square-and-always-multiply and vector-matrix multiplication not based on the vector's density.
+3. "phsmat256s" Sparse implementation, where the multiply step are done with a faster sparse matrix multiplication.
+
+Everything should comply to be benchmarked with SUPERCOP-20200906
\ No newline at end of file