EXHIBIT 5.01
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                      [LETTERHEAD OF FENWICK & WEST LLP]
                                                                                

                               January 25, 1999



VeriSign, Inc.
1390 Shorebird Way
Mountain View, CA 94043-1337


Gentlemen/Ladies:

     At your request, we have examined the Registration Statement on Form S-1
(File Number 333-70121) (the "Registration Statement") filed by you with the
Securities and Exchange Commission (the "Commission") on or about January 5,
1999, as subsequently amended, in connection with the registration under the
Securities Act of 1933, as amended, of an aggregate of 2,760,000 shares of your
Common Stock (the "Stock"), 1,565,000 of which are presently issued and
outstanding and will be sold by certain selling stockholders (the "Selling
Stockholders").

     In rendering this opinion, we have examined the following:

     (1)  your registration statement on Form S-1 (File Number 333-40789) filed
          with and declared effective by the Commission on January 29, 1998,
          together with the Exhibits filed as a part thereof;

     (2)  your registration statement on Form 8-A (File Number 000-23593) filed
          with the Commission on January 5, 1998;

     (3)  the Registration Statement, together with the Exhibits filed as a part
          thereof;

     (4)  the Prospectuses prepared in connection with the Registration
          Statement;

     (5)  the minutes of meetings and actions by written consent of the
          stockholders and Board of Directors that are contained in your minute
          books that are in our possession;

     (6)  your stock records that you have provided to us (consisting of a
          certificate from your transfer agent verifying the number of your
          issued and outstanding shares of capital stock as December 31, 1998
          and a list of option and warrant holders respecting your capital and
          of any rights to purchase capital stock that was prepared by you and
          dated December 31, 1998, verifying the number of such issued and
          outstanding securities).

 
January 25, 1999
Page 2


     (7)  a Management Certificate addressed to us and dated of even date
          herewith executed by the Company containing certain factual and other
          representations.

     (8)  The various stock purchase and other agreements under which the
          Selling Stockholders acquired the Stock to be sold by them as
          described in the Registration Statement.

     (9)  the Custody Agreement and Powers of Attorney signed by the Selling
          Stockholders in connection with the sale of Stock described in the
          Registration Statement.

     By telephone call to the offices of the Commission, we have also confirmed
the continued effectiveness of the Company's registration under the Securities
Exchange Act of 1934, as amended (the "Exchange Act"), and the timely filing by
you of all reports required to be filed by you pursuant to Rules 13, 14 and 15
promulgated under the Exchange Act.

     In our examination of documents for purposes of this opinion, we have
assumed, and express no opinion as to, the genuineness of all signatures on
original documents, the authenticity of all documents submitted to us as
originals, the conformity to originals of all documents submitted to us as
copies, the legal capacity of all natural persons executing the same, the lack
of any undisclosed terminations, modifications, waivers or amendments to any
documents reviewed by us and the due execution and delivery of all documents
where due execution and delivery are prerequisites to the effectiveness thereof.

     As to matters of fact relevant to this opinion, we have relied solely upon
our examination of the documents referred to above and have assumed the current
accuracy and completeness of the information obtained from public officials and
records referred to above.  We have made no independent investigation or other
attempt to verify the accuracy of any of such information or to determine the
existence or non-existence of any other factual matters; however, we are not
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aware of any facts that would cause us to believe that the opinion expressed
herein is not accurate.

     We are admitted to practice law in the State of California, and we express
no opinion herein with respect to the application or effect of the laws of any
jurisdiction other than the existing laws of the United States of America and
the State of California and (without reference to case law or secondary sources)
the existing Delaware General Corporation Law.

     Based upon the foregoing, it is our opinion that the 1,565,000 shares of
Stock to be sold by the Selling Stockholders pursuant to the Registration
Statement are legally issued, fully paid and nonassessable and that the up to
1,195,000 shares of Stock to be issued and sold by you, when issued and sold in
accordance in the manner referred to in the relevant Prospectus associated with
the Registration Statement, will be validly issued, fully paid and
nonassessable.

 
January 25, 1999
Page 3


     We consent to the use of this opinion as an exhibit to the Registration
Statement and further consent to all references to us, if any, in the
Registration Statement, the Prospectus constituting a part thereof and any
amendments thereto.

     This opinion speaks only as of its date and we assume no obligation to
update this opinion should circumstances change after the date hereof.  This
opinion is intended solely for the your use as an exhibit to the Registration
Statement for the purpose of the above sale of the Stock and is not to be relied
upon for any other purpose.

                                  Very truly yours,

                                  FENWICK & WEST LLP

                                  By:  /s/ Jeffrey Vetter
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                                     Jeffrey Vetter, a Partner