<h1>Aadhaar biometric privacy restricted to authentication, unauthorized sharing criminalized and entities must follow encryption and safeguards.</h1> Linking of Aadhaar with PAN and bank accounts uses a multi entity authentication model with PKI encryption, secured private connectivity, and UIDAI security guidelines; only authentication success/failure is transmitted. Core biometric information is prohibited from sharing or use beyond Aadhaar number generation and authentication, biometric data is deemed sensitive personal information under the IT framework, and unauthorized disclosure is subject to penalties and criminal sanctions under the Aadhaar Act.