Aadhaar

# Aadhaar ## What is Aadhaar? Aadhaar is India’s national digital identity system maintained by UIDAI (Unique Identification Authority of India). * It is a **12-digit unique identity number** issued to residents of India, based on their biometric and demographic data. * Aadhaar serves as a **foundational ID** that can be used to verify identity across financial, telecom, and government services. * Verification is done via UIDAI APIs or Aadhaar-linked services, such as QR codes. :::warning Because of how UIDAI signs Aadhaar data, Aadhaar-derived uniqueness is weaker than passport-derived uniqueness: in rare edge cases (for example a legal name change) the same person can verify as new. If sybil resistance is critical to your use case, contact us before relying on Aadhaar alone. ::: ## Registering with Aadhaar on Self Self allows users to prove identity using Aadhaar in a **privacy-preserving** way. There are two common methods: 1. #### Using the mAadhaar app 1. #### Download the official **mAadhaar app** from UIDAI ([Android](https://play.google.com/store/apps/details?id=in.gov.uidai.mAadhaarPlus)/[IOS](https://apps.apple.com/in/app/maadhaar/id1435469474)). 2. #### Inside the app, generate a **QR code** that contains Aadhaar demographic details. <figure><img loading="lazy" src="/docs/docs-assets/WhatsApp Image 2025-09-26 at 00.13.52.avif" alt="" width="149"><figcaption><p>mAadhaar</p></figcaption></figure> 3. #### Upload this QR code in the Self app to register. 1. #### Self processes this QR to derive a unique **nullifier** (an identifier) that allows users to prove uniqueness without sharing their Aadhaar number directly. 2. #### By using the UIDAI website 1. #### Go to the [UIDAI website](https://myaadhaar.uidai.gov.in/genricDownloadAadhaar/en) 2. #### Enter your Aadhaar number, and verify yourself with an OTP to get a PDF. 3. #### Take a screenshot of the QR code in the pdf and upload in the Self app. :::note The password to the PDF in both cases is the first four letters of your name in caps following by your birth year. ::: ## Working with attributes in Aadhaar Since Aadhaar uses a different format than passports, keep in mind that some of the disclosed attribute formats can be different. ### `GenericDiscloseOutputV2` <table><thead><tr><th>Field </th><th>Type</th><th>Formatting / Value</th></tr></thead><tbody><tr><td><pre><code>forbiddenCountriesListPacked </code></pre></td><td><code>uint256[4]</code></td><td>Packed bytes of all countries into an array 4 <code>uint256</code> numbers.</td></tr><tr><td><pre><code>issuingState </code></pre></td><td><code>string</code></td><td>Varies**</td></tr><tr><td><pre><code>name </code></pre></td><td><code>string[]</code></td><td>First value contains the entire name (and it may vary)</td></tr><tr><td><pre><code>idNumber </code></pre></td><td><code>string</code></td><td>Last 4 letters of the aadhaar number. </td></tr><tr><td><pre><code>nationality </code></pre></td><td><code>string</code></td><td><code>'IND'</code></td></tr><tr><td><pre><code>dateOfBirth </code></pre></td><td><code>string</code></td><td><code>DD-MM-YYYY</code></td></tr><tr><td><pre><code>gender </code></pre></td><td><code>string</code></td><td><code>'M' | 'T' | 'F'</code></td></tr><tr><td><pre><code>expiryDate </code></pre></td><td><code>string</code></td><td><code>'UNAVAILBLE'</code></td></tr><tr><td><pre><code>olderThan </code></pre></td><td><code>uint256</code></td><td><code>0 - 99</code></td></tr><tr><td><pre><code>ofac </code></pre></td><td><code>bool[3]</code></td><td>Each value is true if ofac check is enabled.</td></tr></tbody></table> ### `GenericDiscloseOutput` <table><thead><tr><th>Field</th><th>Type</th><th>Formatting / Value</th></tr></thead><tbody><tr><td><pre><code>forbiddenCountriesListPacked </code></pre></td><td><code>string[]</code></td><td>Packed bytes list of forbidden countries</td></tr><tr><td><pre><code>issuingState </code></pre></td><td><code>string</code></td><td>Varies</td></tr><tr><td><pre><code>name </code></pre></td><td><code>string</code></td><td>Full name. Can vary as well</td></tr><tr><td><pre><code>idNumber </code></pre></td><td><code>string</code></td><td>Last 4 digits of aadhaar</td></tr><tr><td><pre><code>nationality </code></pre></td><td><code>string</code></td><td><code>'IND'</code></td></tr><tr><td><pre><code>dateOfBirth </code></pre></td><td><code>string</code></td><td><code>YYYYMMDD</code></td></tr><tr><td><pre><code>gender </code></pre></td><td><code>string</code></td><td><code>'M' | 'T' | 'F'</code></td></tr><tr><td><pre><code>expiryDate </code></pre></td><td><code>string</code></td><td><code>'UNAVAILABLE'</code></td></tr><tr><td><pre><code>minimumAge </code></pre></td><td><code>string</code></td><td><code>'00'-'99'</code> </td></tr><tr><td><pre><code>ofac </code></pre></td><td><code>bool[]</code></td><td>True if in ofac</td></tr></tbody></table> :::note \*\*Varies refers to a string being all caps / lowercase / first letter in caps and the rest in lowercase. :::