**EXHIBIT 31.2**

 

**CERTIFICATION OF PERIODIC REPORT UNDER SECTION 302 OF**

**THE SARBANES-OXLEY ACT OF 2002**

 

I, Andrew Hamer, certify that: 

 

1. I havereviewed this Amendment No. 1 to annual report on Form 10-K/A of Keynote Systems, Inc.; 

 

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 underwhich such statements were made, not misleading with respect to the period covered by this report; 

 

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 cashflows of the registrant as of, and for, the periods presented in this report; 

 

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) and 15d-15(e)) and internal control over financialreporting (as defined in Exchange Act Rules 13a-15(f) and 15(d)-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 our supervision, toensure 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 report is being prepared; 

 

b) Designed such internal control over financial reporting, or caused suchinternal 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 for external purposes in accordance withgenerally accepted accounting principles; 

 

c) Evaluatedthe effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based onsuch evaluation; and 

 

d) Disclosed in this report anychange in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal year that has materially affected, or is reasonably likely to materially affect, the registrant’s internalcontrol over financial reporting. 

5. The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation ofinternal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors: 

 

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonablylikely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and 

 

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internalcontrol over financial reporting. 

 

Date: January 30, 2006 

 

/s/ ANDREW HAMER    

**Andrew Hamer**

**Vice President and Chief Financial Officer**