Electronic Signature Legality

1. The Three Signature Tiers

Modern electronic transaction laws — anchored by eIDAS in the EU and mirrored across the GCC — recognise a ladder of signature types with increasing evidentiary weight:

Simple Electronic Signature (SES)

Any data in electronic form which is attached to, or logically associated with, other electronic data and used by the signer to sign (eIDAS Art. 3(10)). A typed name, a click-to-sign, or an email-OTP-authenticated signature all qualify. SES is legally binding for the overwhelming majority of commercial transactions.

Advanced Electronic Signature (AES)

An SES that additionally (eIDAS Art. 26): (a) is uniquely linked to the signer; (b) is capable of identifying the signer; (c) is created using electronic signature-creation data the signer can, with a high level of confidence, use under their sole control; and (d) is linked to the signed data such that any subsequent change is detectable. AES typically requires a signer-held private key bound to verified identity.

Qualified Electronic Signature (QES)

An AES created by a qualified signature creation device and based on a qualified certificate issued by a qualified trust service provider (eIDAS Art. 3(12)). QES is the only tier that eIDAS Art. 25(2) deems legally equivalent to a handwritten signature by operation of law.

2. What SahlSign Provides

Against those definitions, the SahlSign signature is an SES with technical integrity guarantees. Specifically, every signed document produced by the Service includes:

• Signer identification via email and one-time password (OTP): each signer must access the document through a unique time-limited link delivered to their email address and, where configured, verify a one-time code.
• PAdES-B-T compliant seal: a CMS/PKCS#7 signature block embedded into the PDF according to ETSI EN 319 142 (PAdES Baseline-T profile), applied by SahlSign as the trust service operator on behalf of the originating tenant organisation. The tenant identity appears in the document metadata, the signing-request email (“Processed by SahlSign on behalf of [organisation]”), and the Certificate of Completion.
• Qualified timestamp: an RFC 3161 timestamp obtained from a third-party Time Stamping Authority (TSA) at the moment of sealing, providing evidence of the time of signature that does not depend on our servers.
• Cryptographic audit chain: every event in the signing workflow (document sent, viewed, signed, completed) is recorded as an audit entry whose hash is linked to the hash of the previous entry. Any modification to any entry invalidates all subsequent entries.
• Certificate of Completion: a standalone PDF that summarises the signers, the final document hash, the audit trail, and a verification URL anyone can use to re-check the integrity of the document.

These technical measures give SahlSign signatures evidentiary weight comparable to some AES implementations and superior to the default SES offered by many competitors. They do not, however, meet the statutory definition of AES under eIDAS Art. 26 (sole-control and unique-identification requirements) or KSA ETL Art. 14 (accredited-CA-issued signatures).

3. Legal Recognition by Jurisdiction

The table below summarises the primary legal instrument under which SES signatures produced by SahlSign are recognised in each jurisdiction we serve.

The practical effect: a document signed through SahlSign is admissible in evidence and legally binding in every jurisdiction above for the commercial transactions common to day-to-day business. Where statute or regulation requires a specific signature form (see Section 4 below), a higher tier is necessary.

4. When a Higher Tier Is Required

You should not rely on SahlSign SES alone for the following categories of transaction, which in most jurisdictions we serve require notarisation, registration with a government authority, or a specific form of signature that SES does not meet. You are responsible for confirming the requirements applicable to your transaction:

• Transfers of real property (title deeds, registered leases) that must be recorded with a land registry;
• Wills, testamentary instruments, and inheritance documents;
• Powers of attorney where local law mandates notarisation or consular attestation;
• Marriage, divorce, and other personal-status instruments;
• Documents filed directly with a court, unless the court explicitly accepts electronic signatures of the tier we provide;
• Government tender submissions that require QES or a signature from a nationally accredited trust service provider;
• Certain regulated financial products (for example, Shariah-compliant murabaha contracts at some institutions) where the bank’s internal policy requires wet-ink or QES.

In all these cases, consult local counsel. SahlSign can provide an audit-ready Certificate of Completion that some authorities accept as supplementary evidence even where a wet-ink or notarised original is also required.

5. Verifying a SahlSign Signature

Every completed document can be verified by any party, not just the parties to the transaction:

1. Open the Certificate of Completion PDF. It contains the document ID and a verification URL.
2. Visit the verification URL in any browser. SahlSign will display the document’s final hash, signers, and audit trail status.
3. Independently verify the PDF is unmodified by opening it in Adobe Acrobat Reader: the embedded PAdES seal and TSA timestamp are validated automatically and any modification to the bytes will be flagged.
4. Advanced users can verify the cryptographic audit chain by hashing the audit entries in order and comparing against the chain head stored on the SahlSign side.

6. Roadmap: AES and QES

SahlSign’s roadmap includes optional step-up to AES and QES via partnerships with accredited trust service providers. This is typically only required for a narrow set of regulated workflows (banking onboarding, government tenders, specific regulated insurance products). If your use case requires AES or QES, contact sales@sahlsign.com and we will discuss options including Nafath (KSA), UAE Pass, and EU-based qualified providers.

7. This Is Not Legal Advice

The information on this page is provided for general informational purposes and reflects our reasonable understanding of the referenced legal instruments as of the date above. It is not legal advice. Before relying on an electronic signature for a material transaction, you should consult a qualified lawyer licensed in the relevant jurisdiction.

8. Contact

Questions about the signature tier, evidentiary weight, or verification? Email legal@sahlsign.com.