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|   | þ | QUARTERLY      REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF      1934 |
|--------|--------|---------------------------------------------------------------------------------------------------|

|   | For      the Quarterly Period Ended March 31,2008 |
|--------|---------------------------------------------------|

|   | o | TRANSITION      REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF      1934 |
|--------|---|-----------------------------------------------------------------------------------------------------|

|   | For      the Transition Period From _____ to_____ |
|--------|---------------------------------------------------|

| Delaware                             | 33-0732700                  |
|--------------------------------------|-----------------------------|
| (State      or other jurisdiction of | (IRS      Employer          |
| Incorporation      or Organization)  | Identification      Number) |

| Large accelerated      filer o                             | Accelerated filer      þ    |
|------------------------------------------------------------|----------------------------------|
|                                                       |                             |
| Non-accelerated      filer o      | Smaller reporting      company o |

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| PART II.                | OTHER INFORMATION |
|-------------------------|-------------------|
| Item 6.                 | Exhibits          |
| Signatures              |              |
| Index to      Exhibits  |              |
| Exhibit 10.1            |              |
| Exhibit      31.1  |              |
| Exhibit 31.2            |              |

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PART II 

Item6.

| ExhibitNumber                                              | Exhibit                                                                                                      | Incorporated      by Reference |             |
|------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------|--------------------------------|------------------|
| Form                                                       | File      No.                                                                                                | Exhibit                        | Filing      Date | Filed      Herewith |
|                                                       |                                                                                                         |                           |             |   |   |   |
|               10.1 | hi/fn,      inc. Amended and Restated 1998 Employee Stock Purchase Plan, as amended on      Febuary 21, 2008 |                           |             |   |   | X |
|               31.1 | Certification      of Chief Executive Officer pursuant to Rule 13A-14(a) or      15D-14(a)                   |                           |             |   |   | X |
|               31.2      | Certification      of Chief Financial Officer pursuant to Rule 13A-14(a) or      15D-14(a)                   |                           |             |   |   | X |
|                                                       |                                                                                                         |                           |             |   |   |   |

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SIGNATURES

|                          | hi/fn,inc.                                                                                                                 |   |
|-------------------------------|----------------------------------------------------------------------------------------------------------------------------|--------|
|                          | (Registrant)                                                                                                               |   |
|                          |                                                                                                                       |   |
|                          |                                                                                                                  |   |
|  Date: May 28,      2008 | By: /s/ William      R. Walker                                                                                   |   |
|                          | William R.      Walker                                                                                                     |   |
|                          | Vice      President, Finance, Chief Financial Officer and Secretary (principal      financial and accounting officer) |   |

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INDEX TO EXHIBITS

| ExhibitNumber                                              |  Exhibit                                                                                                | Incorporated      by Reference |             |
|------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------|--------------------------------|------------------|
| Form                                                       | File      No.                                                                                                | Exhibit                        | Filing      Date | Filed      Herewith |
|                                                       |                                                                                                         |                           |             |   |   |   |
|               10.1 | hi/fn,      inc. Amended and Restated 1998 Employee Stock Purchase Plan, as amended on      Febuary 21, 2008 |                           |             |   |   | X |
|               31.1 | Certification      of Chief Executive Officer pursuant to Rule 13A-14(a) or      15D-14(a)                   |                           |             |   |   | X |
|               31.2 | Certification      of Chief Financial Officer pursuant to Rule 13A-14(a) or      15D-14(a)                   |                           |             |   |   | X |
|                                                       |                                                                                                         |                           |             |   |   |   |

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