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EXHIBIT 12.1

CERTIFICATIONS

I, Yanki Margalit,
certify that:

|1.  I have reviewed this annual report on
  Form 20-F of Aladdin Knowledge Systems Ltd.;                                                                                                                                                                                                                                            
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|2.  Based on my knowledge, this annual
  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 annual report;
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|3.  Based on my knowledge, the financial
  statements, and other financial information included in this annual report,
  fairly present in all material respects the financial condition, results of
  operations and cash flows of the registrant as of, and for, the periods
  presented in this annual report;                   
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|4.  The registrant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)) for the
  registrant and have:                                                                                                             
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|5.  The registrants other certifying
  officer and I have disclosed, based on our most recent evaluation of internal
  control over financial reporting, to the registrants auditors and the audit
  committee of registrants board of directors (or persons performing the
  equivalent function):                              
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|June 28, 2004 | /s/ Yanki Margalit                     
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|              | Yanki MargalitChief
  Executive Officer



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