<PAGE>


                                                                    EXHIBIT 31.1

             RULE 13A-14(A) CERTIFICATION OF CHIEF EXECUTIVE OFFICER

I, Richard J. Lampen, certify that:

1.    I have reviewed this quarterly report on Form 10-QSB of CDSI Holdings
      Inc.;

2.    Based on my knowledge, this report does not contain any untrue statement
      of a material fact or omit to state a material fact necessary to make the
      statements made, in light of the circumstances under which such statements
      were made, not misleading with respect to the period covered by this
      report;

3.    Based on my knowledge, the financial statements, and other financial
      information included in this report, fairly present in all material
      respects the financial condition, results of operations and cash flows of
      the small business issuer as of, and for, the periods presented in this
      report;

4.    The small business issuer's other certifying officer and I are responsible
      for establishing and maintaining disclosure controls and procedures (as
      defined in Exchange Act Rules 13a-15(e) and 15d-15(e) for the small
      business issuer and have:

      (a)   designed such disclosure controls and procedures, or caused such
            disclosure controls and procedures to be designed under our
            supervision, to ensure that material information relating to the
            small business issuer is made known to us by others within those
            entities, particularly during the period in which this report is
            being prepared;

      (b)   [intentionally omitted];

      (c)   evaluated the effectiveness of the small business issuer's
            disclosure controls and procedures and presented in this report our
            conclusions about the effectiveness of the disclosure controls and
            procedures, as of the end of the period covered by this report based
            on such evaluation; and

      (d)   disclosed in this report any change in the small business issuer's
            internal control over financial reporting that occurred during the
            small business issuer's most recent fiscal quarter (the small
            business issuer's fourth fiscal quarter in the case of an annual
            report) that has materially affected, or is reasonably likely to
            materially affect, the small business issuer's internal control over
            financial reporting; and

5.    The small business issuer's other certifying officer and I have disclosed,
      based on our most recent evaluation of internal control over financial
      reporting, to the small business issuer's auditors and the audit committee
      of the small business issuer's board of directors (or persons performing
      the equivalent functions):

      (a)   all significant deficiencies and material weaknesses in the design
            or operation of internal control over financial reporting which are
            reasonably likely to adversely affect the small business issuer's
            ability to record, process, summarize and report financial
            information; and

      (b)   any fraud, whether or not material, that involves management or
            other employees who have a significant role in the small business
            issuer's internal control over financial reporting.


Date: May 1, 2006

                                          /s/ Richard J. Lampen
                                          ------------------------------------
                                          Richard J. Lampen
                                          Chairman and Chief Executive Officer