EX-5

           [LETTERHEAD OF ANTON CAMPION MACDONALD OYLER APPEARS HERE]


May 16, 2000

Certicom Corp.
5520 Explorer Drive
Mississauga, Ontario
L4W 5L1
Canada


Dear Sirs/Mesdames:

Re:  Registration Statement on Form S-8

         We have acted as Yukon Territory counsel for Certicom Corp., a
corporation organized under the laws of the Yukon Territory, Canada (the
"Company"), in connection with the registration of 1,500,000 Common Shares of
the Company (the "Common Shares") issuable under the Certicom Corp. Employee
Stock Purchase Plan and the Certicom Corp. 2000 United States Stock Plan
(collectively, the "Plans"). In connection therewith, we have examined, among
other things, the Registration Statement on Form S-8 (the "Registration
Statement") proposed to be filed by the Company with the Securities and Exchange
Commission on or about May 17, 2000. We have also examined the proceedings and
other actions taken by the Company in connection with the authorization of the
Common Shares issuable under the Plans and such other matters as we deemed
necessary for purposes of rendering this opinion.

         Based upon the foregoing, and in reliance thereon, we are of the
opinion, as of the date hereof, that the Common Shares issuable under the Plans,
when issued, delivered and paid for in accordance with the Plans and in the
manner described in the Registration Statement, will be validly issued, fully
paid and nonassessable.

         In rendering this opinion we express no opinion as to the laws of any
jurisdiction other than the laws of the Yukon Territory.

         We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement. In giving this consent, we do not admit that we are
within the category of persons whose consent is required under Section 7 of the
Securities Act of 1933, as amended, or the General Rules and Regulations of the
Securities and Exchange Commission.

                                  Yours truly,

                                  ANTON CAMPION MACDONALD OYLER

                                  \s\ Gareth C. Howells