[Home](./index.md) > [sip.js](./sip.js.md) > [UserAgentCoreConfiguration](./sip.js.useragentcoreconfiguration.md) > [authenticationFactory](./sip.js.useragentcoreconfiguration.authenticationfactory.md) ## UserAgentCoreConfiguration.authenticationFactory() method DEPRECATED Authentication factory function. Signature: ```typescript authenticationFactory(): DigestAuthentication | undefined; ``` Returns: `DigestAuthentication | undefined`