EXHIBIT 1

JOINT FILING AGREEMENT

This will confirm the agreement by and between each of the undersigned, in accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, that the Schedule 13G filed on or about this date with respect to the beneficial ownership of the undersigned of shares of the Common Stock, par value $.01 per share, of Intrusion Inc., is being filed on behalf of each of the undersigned.  This agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument.

Dated: January 14, 2004
	SCIENCE APPLICATIONS INTERNATIONAL CORPORATION
	By:	/S/ DOUGLAS E. SCOTT
		Name: Douglas E. Scott
		Title: Senior Vice President, General Counsel and Secretary
	SAIC Venture Capital Corporation.
	By:	/S/ GIAN A. BROWN
		Name: Gian A. Brown
		Title: General Counsel

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