**EXHIBIT 31.1**

 

CERTIFICATION OF CHIEF EXECUTIVE OFFICER 

 

I, Thomas E. Noonan, Chief Executive Officer and President of Internet Security Systems, Inc., certify that: 

 

1. I have reviewed this quarterly report on Form 10-Q of Internet SecuritySystems, Inc. (the “Registrant”); 

 

2. Based on myknowledge, this quarterly 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 misleadingwith respect to the period covered by this quarterly report; 

 

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

 

4. Registrant’s other certifying officer and I am responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting(as defined in Exchange Act Rules 13a-15(f) and 15d-15(f) for the Registrant and have: 

 

a. designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under oursupervision, to ensure that material information relating to the Registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this quarterly report is beingprepared; 

 

b. designed such internal controlover financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements forexternal purposes in accordance with generally accepted accounting principles; 

 

c. evaluated the effectiveness of the Registrant’s disclosure controls and procedures and presented in this quarterly report ourconclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this quarterly report based on such evaluation; and 

 

d. disclosed in this quarterly report any change in the Registrant’s internal control over financialreporting that occurred during Registrant’s first quarter of fiscal 2005 that has materially affected, or is reasonably likely to materially affect, the Registrant’s internal control over financial reporting; and 

 

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

 

a. all significant deficiencies and material weaknesses inthe design or operation of internal control over financial reporting which are reasonably likely to adversely affect the Registrant’s ability to record, process, summarize and report financial information; and 

 

b. any fraud, whether or not material, that involvesmanagement or other employees who have a significant role in Registrant’s internal control over financial reporting.