@Misc{Riv00,
  author = 	 { Ronald L. Rivest },
  title = 	 { Two signature schemes },
  howpublished = { Talk given October 17, 2000 at Cambridge University. },
  date =         { 2000-10-17 },                  
  urla =         { <a href="#MR02b">scheme 1:MR02b</a> },
  urlb =         { <a href="#CRR02">scheme 2:CRR02</a> },
  OPTyear = 	 { 2000 },
  OPTmonth = 	 { October 17, },
}