Aadhaar is the world's largest biometric identity system with approximately 134 crore live Aadhaar holders

1. At a Glance

• Aadhaar = 12-digit unique identity number issued by UIDAI (Unique Identification Authority of India) using demographic + biometric data (fingerprint, iris, face) [1][3].
• World's largest biometric ID system with ~134 crore live Aadhaar holders and >17,000 crore authentication transactions completed [1].
• Backbone of India's Digital Public Infrastructure (DPI) — enables DBT, JAM trinity, e-KYC, subsidy delivery [1][3].
• High UPSC salience: cuts across GS-II (governance, rights, SC judgments), GS-III (digital economy, cybersecurity) and ethics (privacy).

2. Why in the News

• PIB release dated 18 March 2026 by Ministry of Electronics & IT reiterated Aadhaar scale (~134 crore holders), encryption of demographic data at rest and in transit, and that storage/processing of Aadhaar data occurs within India [1].
• Continued focus on data localisation, privacy safeguards, and authentication ecosystem expansion (OTP, biometric, face) [1].

3. Background & Evolution

• 2009: UIDAI constituted by executive notification under Planning Commission (28 Jan 2009).
• 2010: First Aadhaar number issued in Maharashtra (Tembhli village, Sept 2010).
• 2016: Aadhaar (Targeted Delivery of Financial and Other Subsidies, Benefits and Services) Act, 2016 enacted; UIDAI given statutory status on 12 July 2016 under MeitY [2][3].
• 2017: SC in Justice K.S. Puttaswamy v. UoI declared Right to Privacy a fundamental right (Art. 21).
• 2018: SC (26 Sept 2018) upheld constitutional validity of Aadhaar Act; struck down mandatory linking with bank accounts and mobile; allowed mandatory link for PAN (Sec 139AA IT Act) and subsidies from Consolidated Fund of India [4].
• 2019: Aadhaar and Other Laws (Amendment) Act, 2019 (Act 14 of 2019, effective 25 July 2019) — enabled voluntary use for bank/SIM via offline KYC [2].

4. Core Static Facts

• Implementing body: UIDAI — statutory authority under MeitY (Ministry of Electronics & IT) [2].
• Enabling Act: Aadhaar Act, 2016; amended 2019 [2][3].
• Headquarters: New Delhi; 8 Regional Offices.
• Aadhaar number: 12-digit random; issued to residents (not citizens) staying ≥182 days in preceding 12 months.
• Data: Demographic (name, DOB, address, gender) + Biometric (10 fingerprints, 2 iris, photograph).
• Authentication modes: OTP, biometric (fingerprint/iris/face), demographic [1].
• Live Aadhaar holders: ~134 crore [1].
• Authentication transactions: >17,000 crore cumulative [1].
• Data storage: Within India; demographic data encrypted at rest and in transit [1].
• Core biometric data: Cannot be shared with anyone for any reason (Aadhaar Regulations, 2016) [2].

5. Multi-Dimensional Analysis

• Legal / Constitutional
• SC in Puttaswamy (2018) upheld Act but read down Sec 33(2), 47, 57; struck down mandatory bank/SIM linking [4].
• Aadhaar mandatory only for benefits/subsidies/services from Consolidated Fund of India [4].

• Sec 139AA Income Tax Act (Aadhaar-PAN link) upheld as not violating Art. 14 [4].

• Administrative / Governance

• Enables JAM trinity (Jan Dhan–Aadhaar–Mobile) → leak-proof DBT; cumulative DBT savings reported in lakh crores.

• e-KYC reduced onboarding time/cost for telecom, banking.

• Scientific / Technological

• Multi-modal biometric de-duplication at population scale; encryption at rest + transit; data localisation within India [1].

• Ethical / Privacy

• Tensions: surveillance risk, exclusion errors in PDS authentication, biometric failures of elderly/manual labourers.

• 2019 amendment introduced offline verification and virtual ID to mitigate.

• Economic

• Backbone of DPI exports (India Stack); referenced by World Bank as a model for digital ID.

6. Recent Developments (last 12-18 months)

• 18 March 2026: PIB/MeitY communication — 134 cr live holders, >17,000 cr authentications; reaffirmed encryption + in-India storage [1].
• Continued rollout of Face Authentication as biometric mode [1].

7. Prelims Hooks

• UIDAI is under MeitY, not Ministry of Home Affairs [2].
• UIDAI became statutory on 12 July 2016 under the Aadhaar Act, 2016 [2].
• Aadhaar Act 2016 was passed as a Money Bill (later challenged; upheld in Puttaswamy 2018) [4].
• Sec 139AA of Income Tax Act mandates Aadhaar-PAN linkage; upheld by SC [4].
• Aadhaar mandatory only for subsidies from Consolidated Fund of India [4].
• Aadhaar is issued to residents, not citizens (≥182 days in preceding 12 months).
• First Aadhaar issued in 2010 in Maharashtra (Tembhli, Nandurbar).
• 2019 Amendment Act introduced offline KYC and Virtual ID.
• Core biometric data cannot be shared with anyone (per 2016 Regulations) [2].
• >17,000 crore authentication transactions; ~134 crore live holders [1].
• Demographic data stored encrypted at rest and in transit, processed within India [1].
• Aadhaar authentication modes: OTP, fingerprint, iris, face, demographic [1].

8. Mains Relevance

• GS-II: Governance — e-Governance applications; Government policies for vulnerable sections; SC judgments on rights.
• GS-III: Indian economy — Digital economy, DBT, cybersecurity, data protection.
• GS-IV: Ethics — Privacy vs welfare delivery; informed consent.
• Likely stems:
• "Aadhaar has transformed welfare delivery but raises questions on privacy and exclusion. Discuss."
• "Examine the impact of the Puttaswamy judgments (2017, 2018) on the Aadhaar ecosystem." [4]
• "Digital Public Infrastructure built around Aadhaar is India's most significant export-grade governance innovation. Critically evaluate." [1]

9. Related Topics to Study Next

• Puttaswamy judgments (2017 & 2018) — privacy as fundamental right [4].
• Digital Personal Data Protection Act, 2023 — privacy framework around Aadhaar data.
• JAM Trinity & DBT Mission — operational use of Aadhaar.
• India Stack / DPI — UPI, DigiLocker, Account Aggregator built on Aadhaar.
• PMJDY (Jan Dhan) — financial inclusion leg of JAM.
• NPCI & AePS — Aadhaar-enabled Payment System.
• Section 139AA Income Tax Act — PAN-Aadhaar linkage [4].
• Aadhaar & Other Laws (Amendment) Act, 2019 — voluntary use, offline KYC [2].

10. Common Errors / Trap Areas

• UIDAI is under MeitY, NOT MHA or NITI Aayog [2].
• Aadhaar issued to residents, NOT citizens — confuses many.
• Aadhaar Act passed in 2016, but UIDAI itself was set up in 2009 by executive order.
• SC did NOT strike down the Act in entirety in 2018 — it upheld it with reading down of Sec 33(2), 47, 57 [4].
• Bank-account and mobile-SIM linkage is NOT mandatory post-2018 ruling [4].
• Storage is within India — do not confuse with cross-border cloud data [1].