Certicom said it received a second takeover bid from Research In Motion, this one for for 3 Canadian dollars a share, in what could lead to a bidding war with rival VeriSign. In a news release Tuesday, Certicom, which had previously accepted an offer of 2.10 Canadian dollars a share from VeriSign, said a special committee of its board is reviewing the new bid. If Certicom, a Canadian maker of encryption software, accepts the Research In Motion bid, VeriSign would have five days to improve its offer.