-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 VAf1y20HztcwynCb4GuLKAGWdzWmeOxQVNIOoZCM/9vIP2u2psOw7IBc5gBZB1/6
 RFKfrHYxoKWlKHu1uGpOhw==

<SEC-DOCUMENT>0001179110-04-020410.txt : 20041101
<SEC-HEADER>0001179110-04-020410.hdr.sgml : 20041101
<ACCEPTANCE-DATETIME>20041101131219
ACCESSION NUMBER:		0001179110-04-020410
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20041020
FILED AS OF DATE:		20041101
DATE AS OF CHANGE:		20041101

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CAPUTO ANTHONY A
		CENTRAL INDEX KEY:			0001271635

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-11447
		FILM NUMBER:		041109052

	BUSINESS ADDRESS:	
		STREET 1:		C/O SAFENET INC
		STREET 2:		8029 CORPORATE DRIVE
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21236
		BUSINESS PHONE:		4109317500

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			DATAKEY INC
		CENTRAL INDEX KEY:			0000704914
		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS ELECTRICAL MACHINERY, EQUIPMENT & SUPPLIES [3690]
		IRS NUMBER:				411291472
		STATE OF INCORPORATION:			MN
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		407 W TRAVELERS TRAIL
		CITY:			BURNSVILLE
		STATE:			MN
		ZIP:			55337
		BUSINESS PHONE:		6128906850

	MAIL ADDRESS:	
		STREET 1:		407 WEST TRAVELERS TRAIL
		CITY:			BURNSVILLE
		STATE:			MN
		ZIP:			55337
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 3 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2004-10-20</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000704914</issuerCik>
        <issuerName>DATAKEY INC</issuerName>
        <issuerTradingSymbol>DKEY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001271635</rptOwnerCik>
            <rptOwnerName>CAPUTO ANTHONY A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1280 CONTINENTAL LINE LANE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WEST CHESTER</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19382</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>No securities beneficially owned</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>Kristen Carter of SafeNet, Inc. for Anthony A. Caputo</signatureName>
        <signatureDate>2004-11-01</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----