**EXHIBIT 31.1**

 

### **Rule 13a-14(a)/15d-14(a) CERTIFICATION**

### ** **

I, Patrick F. O’Neal,certify that:

 

1.                                       Ihave reviewed this Amendment No. 1 to Quarterly Report on Form 10-QSB/A for thethree months ended June 30, 2005 of SentoCorporation;

 

2.                                       Basedon my knowledge, this report does not contain any untrue statement of amaterial fact or omit to state a material fact necessary to make the statementsmade, in light of the circumstances under which such statements were made, notmisleading with respect to the period covered by this report;

 

3.                                       Based on my knowledge, the financialstatements, and other financial information included in this report, fairlypresent in all material respects the financial condition, results of operationsand cash flows of the small business issuer as of, and for, the periodspresented in this report;

 

4.                                       The small business issuer’s other certifyingofficer(s) and I are responsible for establishing and maintaining disclosurecontrols and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) for the small business issuer and have:

 

(a)                                  designed such disclosure controls andprocedures, or caused such disclosure controls and procedures to be designedunder our supervision, to ensure that material information relating to thesmall business issuer, including its consolidated subsidiaries, is made knownto us by others within those entities, particularly during the period in whichthis report is being prepared;

 

(b)                                 evaluated the effectiveness of the smallbusiness issuer’s disclosure controls and procedures and presented in thisreport our conclusions about the effectiveness of the disclosure controls andprocedures, as of the end of the period covered by this report based on suchevaluation; and

 

(c)                                  disclosed in this report any change in thesmall business issuer’s internal control over financial reporting that occurredduring the small business issuer’s most recent fiscal quarter (the smallbusiness issuer’s fourth fiscal quarter in the case of an annual report) thathas materially affected, or is reasonably likely to materially affect, thesmall business issuer’s internal control over financial reporting; and

 

5.                                       The small business issuer’s other certifyingofficer(s) and I have disclosed, based on our most recent evaluation of internalcontrol over financial reporting, to the small business issuer’s auditors andthe audit committee of the small business issuer’s board of directors (orpersons performing the equivalent functions):

 

(a)                                  all significant deficiencies and materialweaknesses in the design or operation of internal control over financialreporting which are reasonably likely to adversely affect the small businessissuer’s ability to record, process, summarize and report financialinformation; and

 

(b)                                 any fraud, whether or not material, thatinvolves management or other employees who have a significant role in the smallbusiness issuer’s internal control over financial reporting.

 

 
| Date: August 18,  2005 |                                  |
|-----------------------------|---------------------------------------|
|                        |                                  |
|                        |                                  |
|                        | /s/ PATRICK F. O’ NEAL           |   |
|                        |                                  |
|                        | Patrick F. O’Neal                |
|                        |                                  |
|                        | President and Chief Executive Officer |

 

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