> For the complete documentation index, see [llms.txt](https://docs.emudhradigital.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.emudhradigital.com/readme.md).

# eSign & Signing Services

Legally valid digital signatures from eMudhra — Aadhaar eSign, eKYC-account eSign, remote key storage, organisational remote signing and signature validation.

Welcome to the eMudhra **eSign & Signing Services** documentation — the central hub for integrating legally valid digital signatures into your applications. eMudhra is a CCA-licensed Certifying Authority and empanelled eSign Service Provider (ESP).

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New here? Start with the [Overview](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/) and the [Product Portfolio and Selection Guide](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/product-portfolio-and-selection-guide) to pick the right signing service for your use case.
{% endhint %}

### Signing services

| Product                                                                                                                                              | What it does                                                                                                                | Best for                                                                                 |
| ---------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------- |
| [**eSign v2 — Online Aadhaar**](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/esign-v2-online-aadhaar-ekyc)          | One-time signature after Aadhaar OTP / T-OTP, fingerprint, iris or face authentication. No enrolment.                       | Consumer-scale signing — banks, NBFCs, insurers, government services                     |
| [**eSign v3 — CA eKYC Account**](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/esign-v3-ca-ekyc-account)             | Signing backed by an eKYC account (offline Aadhaar, PAN, bank, organisational KYC). PIN + second factor; up to 5 documents. | Organisational signatories, NRIs, foreign nationals, users without Aadhaar-linked mobile |
| [**Remote Key Storage**](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/remote-key-storage)                           | Long-term DSC held in an eMudhra HSM, unlocked with an AuthPIN; up to 10 documents per authorisation.                       | Frequent signers — CAs, CSs, directors, doctors, approvers                               |
| [**Remote Signing (Document Signer)**](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/remote-signing-document-signer) | Automated, unattended signing with an organisational Document Signer certificate.                                           | Statements, invoices, certificates and other bulk documents                              |
| [**Signature Validation Tool**](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/digital-signature-validation-tool)     | Verifies signatures on PDF, XML and CMS — integrity, chain, revocation and timestamp.                                       | Relying parties, back-office teams, auditors                                             |

### Integrate in four steps

1. **Choose a service** — use the [selection guide](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/product-portfolio-and-selection-guide).
2. **Onboard as an ASP** — sign the ASP–ESP agreement and get UAT credentials ([Onboarding as an ASP](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/onboarding-as-an-asp)).
3. **Build and test** — use the API specifications or the eMudhra Android / iOS SDK, and check the [platform support matrix](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/esign-v2-online-aadhaar-ekyc/integration-models).
4. **Go live** — complete UAT sign-off and the compliance review, then switch to production credentials.

### Popular topics

* [Authentication modes — OTP, T-OTP, fingerprint, iris, face](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/esign-v2-online-aadhaar-ekyc/authentication-modes)
* [KYC types and acceptable POI / POA documents](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/esign-v3-ca-ekyc-account/kyc-types-and-acceptable-documents)
* [Architecture overview](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/architecture-overview)
* [Security and compliance](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/support-and-reference/security-and-compliance)
* [CCA regulatory sources and API specifications](https://emudhra-documents.gitbook.io/esign-and-signing-services/documentation/support-and-reference/regulatory-sources)

### Trusted and compliant

* Licensed Certifying Authority under CCA, India, and empanelled eSign Service Provider
* emSign roots in the Adobe Approved Trust List and Microsoft Trusted Root Program
* FIPS 140-3 Level 3 HSMs, WebTrust-audited, ISO/IEC 27001-certified operations in India

{% hint style="success" %}
Need help? Contact your eMudhra account manager or visit the Help Center.
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