How a digital signature works
A signature on paper is a picture of a hand movement, and a picture can be copied. A digital signature is calculated from the document itself and a secret key, so it fits that document and no other.
Two keys
- Private key. Stays with the signer. It makes the signature.
- Public key. Can be given to anyone. It checks the signature.
Anyone holding the public key can check a signature without asking the signer, and without asking us.
Make a signature yourself
Muna
digital signature
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fingerprint when signed
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fingerprint now
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Madan
digital signature
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The signatures above are real, and they are made in this browser. They are not ePahichan signatures: the keys are generated fresh each time and are tied to no one, so they say that somebody signed, not that a particular person did. Tying a key to a person is what a certificate does.
What a signature does not show
A signature shows who signed what. It does not show when. The time on a device can be set to anything, so proof of time needs a trusted timestamp, which is a separate record.
What the law says
Section 5 of the Electronic Transactions Act, 2063 gives a digital signature legal validity where the law requires a signature, if the signature is made by the procedures in the Act and the Rules made under it. The Act does not cover every document: deeds that transfer title to land, wills, negotiable instruments and powers of attorney are excluded.
Read more in our guides and the glossary.