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UNITED STATESSECURITIES AND
EXCHANGE COMMISSIONWashington, D.C. 20549

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FORM 10-Q/A(Amendment No. 1 to Form 10-Q)

|                                                 |   |  |                                                                                         
|------------------------------------------------ | - |  | ----------------------------------------------------------------------------------------
|                                                 | þ |  | QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 
|For the Quarterly Period Ended December 31, 2004
|                                                
|                                                 |  ̈ |  | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|For the Transition Period From _____ to _____   

COMMISSION FILE NUMBER
0-24765

hi/fn, inc.(Exact
Name of Registrant as specified in its Charter)

| |                                                                |  |                                     | 
| | -------------------------------------------------------------- |  | ----------------------------------- | 
| | Delaware                                                       |  | 33-0732700                          | 
| | (State or other jurisdiction of
incorporation or organization) |  | (I.R.S. EmployerIdentification No.) | 

750 University Avenue,
Los Gatos, California 95032(Address of principal
executive offices and Zip Code)

Registrants
telephone number, including area code: (408) 399-3500

Indicate by check mark whether the
registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the
Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period
that the registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.

YESþ
NO ̈

Indicate by check mark whether the
registrant is an accelerated filer (as defined in Rule 12b-2 of the Exchange Act).

YESþ
NO ̈

The number of shares outstanding of
the Registrants Common Stock, par value $.001 per share, was 14,022,142 at
February 25, 2005.

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# TABLE OF CONTENTS

|                              |                                 | 
|----------------------------- | ------------------------------- | 
|                              |                                 | 
|PART I. FINANCIAL INFORMATION
|                              | Item 4. Controls and Procedures
|Signatures                   
|Index to Exhibits            
|Exhibit 31.1                 
|Exhibit 31.2                 
|Exhibit 32.1                 
|Exhibit 32.2                 

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# EXPLANATORY NOTE

The undersigned registrant hereby
amends the Form 10-Q originally filed on February 9, 2005 (the Form 10-Q)
relating to the Registrants Quarterly Report filing obligations pursuant to Section
13 or 15(d) of the Securities Exchange Act of 1934, as amended, for the sole purpose of
amending Part 1, Item 4 of the Form 10-Q to address comments received from the staff of
the Securities and Exchange Commission. This Form 10-Q/A does not reflect events occurring
after the filing of the Form 10-Q, or modify or update the disclosures therein in any way
other than as required to reflect the amendment set forth below.

# PART I     FINANCIAL
INFORMATION

# Item 4. Controls and
Procedures

Evaluation
of disclosure controls and procedures. We maintain disclosure controls and procedures
that are designed to ensure that information required to be disclosed by us in reports
that we file or submit under the Securities Exchange Act of 1934, as amended, is recorded,
processed, summarized and reported within the time periods specified in Securities and
Exchange Commission rules and forms and that such information is accumulated and
communicated to our management, including our Chief Executive Officer and Chief Financial
Officer, as appropriate to allow timely decisions regarding required disclosure.

Based
on their evaluation as of the end of the period covered by this Quarterly Report on Form
10-Q, our Chief Executive Officer and Chief Financial Officer have concluded that our
disclosure controls and procedures as defined in Rules 13a-15(e) and 15d-15(e) under the
Securities Act of 1934, as amended, are effective to ensure that information required to
be disclosed in this Quarterly Report on Form 10-Q is recorded, processed, summarized and
reported within the time periods specified in SEC rules and forms and is accumulated and
communicated to our Chief Executive Officer and Chief Financial Officer, as appropriate to
allow timely decisions regarding required disclosure.

Changes
in internal control over financial reporting. There was no change in our internal
control over financial reporting that was identified in connection with our evaluation of
disclosure controls and procedures that occurred during the period covered by this
Quarterly Report on Form 10-Q that has materially affected, or is reasonably likely to
materially affect, our internal control over financial reporting.

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SIGNATURES

Pursuant to the requirements of the
Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed
on its behalf by the undersigned thereunto duly authorized.

|                    |  | hi/fn, inc.(Registrant)                                                                                                                                              
|------------------- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
|Date: March 2, 2005 |  | By: /s/ William R. Walker
 William R. WalkerVice President, Finance, Chief Financial Officer and Secretary (principal financial and accounting officer)

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# INDEX TO EXHIBITS

| | Exhibit Number | Exhibit
| | -------------- | -------
| |                |        
| |                | 31.1   
| |                |        
| |                | 31.2   
| |                |        
| |                | 32.1   
| |                |        
| |                | 32.2   

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