<?xml version="1.0" encoding="US-ASCII" ?>
    <!-- Field: Doc-Info; Name: Generator; Value: GoFiler Complete; Version: 6.5a -->
    <!-- Field: Doc-Info; Name: VendorURI; Value: https://www.novaworks.com -->
    <!-- Field: Doc-Info; Name: Status; Value: 0x00000000 -->
    <!-- Field: Doc-Info; Name: Misc; Value: +Kopo7xRiXgen8uEbXpMOaaOyaPty552eYkxvmRwfWlKXyYlcfI7ayvZiQw2YQcC -->
<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xbrldi="http://xbrl.org/2006/xbrldi" xmlns:dei="http://xbrl.sec.gov/dei/2026" xmlns:us-gaap="http://fasb.org/us-gaap/2026" xmlns:srt="http://fasb.org/srt/2026" xmlns:srt-types="http://fasb.org/srt-types/2026" xmlns:ecd="http://xbrl.sec.gov/ecd/2026" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2024-01-31" xmlns:intz="http://intrusion.com/20260331" elementFormDefault="qualified" targetNamespace="http://intrusion.com/20260331">
    <annotation>
      <appinfo>
        <link:roleType roleURI="http://intrusion.com/role/Cover" id="Cover">
          <link:definition>00000001 - Document - Cover</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/CondensedConsolidatedBalanceSheets" id="CondensedConsolidatedBalanceSheets">
          <link:definition>00000002 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/CondensedConsolidatedBalanceSheetsParenthetical" id="CondensedConsolidatedBalanceSheetsParenthetical">
          <link:definition>00000003 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/UnauditedCondensedConsolidatedStatementsOfOperations" id="UnauditedCondensedConsolidatedStatementsOfOperations">
          <link:definition>00000004 - Statement - UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/UnauditedCondensedConsolidatedStatementsOfChangesInStockholdersEquity" id="UnauditedCondensedConsolidatedStatementsOfChangesInStockholdersEquity">
          <link:definition>00000005 - Statement - UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/UnauditedCondensedConsolidatedStatementsOfCashFlows" id="UnauditedCondensedConsolidatedStatementsOfCashFlows">
          <link:definition>00000006 - Statement - UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/DescriptionOfBusiness" id="DescriptionOfBusiness">
          <link:definition>999012 - Disclosure - Description of Business</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/BasisOfPresentation" id="BasisOfPresentation">
          <link:definition>999013 - Disclosure - Basis of Presentation</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/RouAssetsAndLeasingLiabilities" id="RouAssetsAndLeasingLiabilities">
          <link:definition>999014 - Disclosure - ROU Assets and Leasing Liabilities</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/NotesPayable" id="NotesPayable">
          <link:definition>999015 - Disclosure - Notes Payable</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/CommitmentsAndContingencies" id="CommitmentsAndContingencies">
          <link:definition>999016 - Disclosure - Commitments and Contingencies</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/StockholdersEquity" id="StockholdersEquity">
          <link:definition>999017 - Disclosure - Stockholders&#8217; Equity</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/Stock-basedCompensation" id="Stock-basedCompensation">
          <link:definition>999018 - Disclosure - Stock-Based Compensation</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/RevenueRecognition" id="RevenueRecognition">
          <link:definition>999019 - Disclosure - Revenue Recognition</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/CapitalizedSoftwareDevelopment" id="CapitalizedSoftwareDevelopment">
          <link:definition>999020 - Disclosure - Capitalized Software Development</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/NetLossPerShare" id="NetLossPerShare">
          <link:definition>999021 - Disclosure - Net Loss Per Share</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/RelatedPartyTransactions" id="RelatedPartyTransactions">
          <link:definition>999022 - Disclosure - Related Party Transactions</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/SubsequentEvents" id="SubsequentEvents">
          <link:definition>999023 - Disclosure - Subsequent Events</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/RouAssetsAndLeasingLiabilitiesTables" id="RouAssetsAndLeasingLiabilitiesTables">
          <link:definition>999024 - Disclosure - ROU Assets and Leasing Liabilities (Tables)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/RevenueRecognitionTables" id="RevenueRecognitionTables">
          <link:definition>999025 - Disclosure - Revenue Recognition (Tables)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/BasisOfPresentationDetailsNarrative" id="BasisOfPresentationDetailsNarrative">
          <link:definition>999026 - Disclosure - Basis of Presentation (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/Right-of-useAssetAndLeasingLiabilitiesDetails-IncomeStatement" id="Right-of-useAssetAndLeasingLiabilitiesDetails-IncomeStatement">
          <link:definition>999027 - Disclosure - Right-of-use Asset and Leasing Liabilities (Details - Income Statement)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/Right-of-useAssetAndLeasingLiabilitiesDetails-MinimumObligation" id="Right-of-useAssetAndLeasingLiabilitiesDetails-MinimumObligation">
          <link:definition>999028 - Disclosure - Right-of-use Asset and Leasing Liabilities (Details - Minimum obligation)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/RouAssetsAndLeasingLiabilitiesDetailsNarrative" id="RouAssetsAndLeasingLiabilitiesDetailsNarrative">
          <link:definition>999029 - Disclosure - ROU Assets and Leasing Liabilities (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/NotesPayableDetailsNarrative" id="NotesPayableDetailsNarrative">
          <link:definition>999030 - Disclosure - Notes Payable (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/StockholdersEquityDetailsNarrative" id="StockholdersEquityDetailsNarrative">
          <link:definition>999031 - Disclosure - Stockholders&#8217; Equity (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/Stock-basedCompensationDetailsNarrative" id="Stock-basedCompensationDetailsNarrative">
          <link:definition>999032 - Disclosure - Stock-Based Compensation (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/RevenueRecognitionDetails-ContractLiabilities" id="RevenueRecognitionDetails-ContractLiabilities">
          <link:definition>999033 - Disclosure - Revenue Recognition  (Details - Contract liabilities)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/RevenueRecognitionDetailsNarrative" id="RevenueRecognitionDetailsNarrative">
          <link:definition>999034 - Disclosure - Revenue Recognition (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/NetLossPerShareDetailsNarrative" id="NetLossPerShareDetailsNarrative">
          <link:definition>999035 - Disclosure - Net Loss Per Share (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:roleType roleURI="http://intrusion.com/role/RelatedPartyTransactionsDetailsNarrative" id="RelatedPartyTransactionsDetailsNarrative">
          <link:definition>999036 - Disclosure - Related Party Transactions (Details Narrative)</link:definition>
          <link:usedOn>link:presentationLink</link:usedOn>
          <link:usedOn>link:calculationLink</link:usedOn>
          <link:usedOn>link:definitionLink</link:usedOn>
        </link:roleType>
        <link:linkbaseRef xlink:type="simple" xlink:href="intz-20260331_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Presentation Links" />
        <link:linkbaseRef xlink:type="simple" xlink:href="intz-20260331_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Label Links" />
        <link:linkbaseRef xlink:type="simple" xlink:href="intz-20260331_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Calculation Links" />
        <link:linkbaseRef xlink:type="simple" xlink:href="intz-20260331_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Definition Links" />
      </appinfo>
    </annotation>
    <import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />
    <import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" />
    <import namespace="http://xbrl.sec.gov/dei/2026" schemaLocation="https://xbrl.sec.gov/dei/2026/dei-2026.xsd" />
    <import namespace="http://fasb.org/us-gaap/2026" schemaLocation="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd" />
    <import namespace="http://fasb.org/us-types/2026" schemaLocation="https://xbrl.fasb.org/us-gaap/2026/elts/us-types-2026.xsd" />
    <import namespace="http://www.xbrl.org/dtr/type/2024-01-31" schemaLocation="https://www.xbrl.org/dtr/type/2024-01-31/types.xsd" />
    <import namespace="http://xbrl.sec.gov/ecd/2026" schemaLocation="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd" />
    <import namespace="http://xbrl.sec.gov/country/2026" schemaLocation="https://xbrl.sec.gov/country/2026/country-2026.xsd" />
    <import namespace="http://fasb.org/srt/2026" schemaLocation="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd" />
    <import namespace="http://fasb.org/srt-types/2026" schemaLocation="https://xbrl.fasb.org/srt/2026/elts/srt-types-2026.xsd" />
    <element id="intz_SeriesAPreferredStocksMember" name="SeriesAPreferredStocksMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_StockSubscriptionReceivbleMember" name="StockSubscriptionReceivbleMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_OperatingRouLeasesMember" name="OperatingRouLeasesMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_FinanceRouLeasesMember" name="FinanceRouLeasesMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_StreetervilleCapitalMember" name="StreetervilleCapitalMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_StreetervilleDebtMember" name="StreetervilleDebtMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_StreetervilleMember" name="StreetervilleMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_StandbyEquityPurchaseAgreementMember" name="StandbyEquityPurchaseAgreementMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_ReceivedIn2024Member" name="ReceivedIn2024Member" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_ExchangeAgreementMember" name="ExchangeAgreementMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_Section3a9Member" name="Section3a9Member" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_SEPAAgreementMember" name="SEPAAgreementMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_RegisteredDirectOfferingMember" name="RegisteredDirectOfferingMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_PreFundedWarrantsMember" name="PreFundedWarrantsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_CommonStockWarrantsMember" name="CommonStockWarrantsMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_ThreeGovernmentCustomersMember" name="ThreeGovernmentCustomersMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_TopCustomer1Member" name="TopCustomer1Member" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_TopCustomer2Member" name="TopCustomer2Member" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_TopCustomer3Member" name="TopCustomer3Member" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_FourGovernmentCustomersMember" name="FourGovernmentCustomersMember" nillable="true" xbrli:periodType="duration" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" />
    <element id="intz_IssuanceOfCommonStockToReduceNotePayable" name="IssuanceOfCommonStockToReduceNotePayable" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_IssuanceOfCommonStockToReduceNotePayableShares" name="IssuanceOfCommonStockToReduceNotePayableShares" nillable="true" xbrli:periodType="duration" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" />
    <element id="intz_IssuanceOfPreferredStockForPaymentOfPreferredReturn" name="IssuanceOfPreferredStockForPaymentOfPreferredReturn" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_StandbyPurchaseAgreementProceedsNetOfFees" name="StandbyPurchaseAgreementProceedsNetOfFees" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_ProvisionForCreditLosses" name="ProvisionForCreditLosses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_NoncashLeaseCosts" name="NoncashLeaseCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_ProceedsFromRegisteredDirectOffering" name="ProceedsFromRegisteredDirectOffering" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_ProceedsFromStockSubscriptionReceivable" name="ProceedsFromStockSubscriptionReceivable" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_ReductionOfFinanceLeaseLiability" name="ReductionOfFinanceLeaseLiability" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_CapitalizedAssetAndCapitalizedSoftwareIncludedInAccountsPayable" name="CapitalizedAssetAndCapitalizedSoftwareIncludedInAccountsPayable" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_CommonStockIssuedToReduceNotesPayable" name="CommonStockIssuedToReduceNotesPayable" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_PreferredReturnOnPreferredStock" name="PreferredReturnOnPreferredStock" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_ExchangesOfPreferredStockForCommonStock" name="ExchangesOfPreferredStockForCommonStock" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_AmortizationOfPreferredStockExchangePremium" name="AmortizationOfPreferredStockExchangePremium" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_DisclosureRouAssetsAndLeasingLiabilitiesAbstract" name="DisclosureRouAssetsAndLeasingLiabilitiesAbstract" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrli:item" />
    <element id="intz_LesseeOperatingAndFinanceLeaseLiabilityPaymentsRemainderOfFiscalYear" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsRemainderOfFiscalYear" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueNextTwelveMonths" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueNextTwelveMonths" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearTwo" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearTwo" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearThree" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearThree" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearFour" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFour" name="LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_FinanceLeaseLiabilityPaymentsDueAfterYearFour" name="FinanceLeaseLiabilityPaymentsDueAfterYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueAfterYearFour" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueAfterYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDue" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDue" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_StandbyEquityPurchaseAgreementValue" name="StandbyEquityPurchaseAgreementValue" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_WarrantsAverageRemainingTerm" name="WarrantsAverageRemainingTerm" nillable="true" xbrli:periodType="duration" type="xbrli:durationItemType" substitutionGroup="xbrli:item" />
    <element id="intz_ContractWithCustomerLiabilityAdditions" name="ContractWithCustomerLiabilityAdditions" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
    <element id="intz_ContractWithCustomerLiabilityRevenueRecognizedIncludingOpeningBalance" name="ContractWithCustomerLiabilityRevenueRecognizedIncludingOpeningBalance" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" />
</schema>
