Types of Electronic or Digital Signatures

Three signature levels—SES, AES, QES—each offering different trust and security.

Types of Electronic Signatures

Electronic signatures are generally classified into three levels under regulations such as eIDAS (EU):

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1. Simple Electronic Signature (SES)

A Simple Electronic Signature (SES) is any electronic data used to indicate acceptance or intent.

Examples

• Typing a name

• Clicking “I Agree”

• Uploading a scanned signature

• Email confirmation

Characteristics

• Confirms intent

• Does not inherently verify identity

• May include audit logs or document sealing (not mandatory)

• Lowest level of assurance

Example: Approving an internal memo.

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2. Advanced Electronic Signature (AES)

An Advanced Electronic Signature (AES) provides higher assurance of signer identity and document integrity.

Must Meet the Following Requirements

• Be uniquely linked to the signer

• Be capable of identifying the signer

• Be under the signer’s sole control

• Detect document modifications (signature becomes invalid if altered)

Common Implementations May Include

• OTP-based verification

• Biometric verification

• Secure cryptographic binding

• Tamper-evident controls

Example: Signing vendor agreements or NDAs.

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3. Qualified Electronic Signature (QES)

A Qualified Electronic Signature (QES) provides the highest level of legal assurance under eIDAS.

Key Characteristics

• Created using a qualified digital certificate

• Issued by a licensed Certificate Authority

• Legally equivalent to handwritten signatures in the EU

In India, This Corresponds To

• Digital Signature Certificates (DSC)

• Issued by licensed Certifying Authorities under the IT Act, 2000

Example: Government filings, regulated financial statements.

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Recommendation

While SES may be legally valid in many cases, AES or QES/DSC-based signatures are recommended for sensitive, high-value, or regulated transactions.