Они именно хотят электронную подпись
Да, электронную. Но не факт, что именно электронно-цифровую:
What is an electronic signature?
Various legal definitions exist for electronic signatures, but the term most generally refers to the acknowledgement or adoption of an electronic message, transaction or document. Some examples include:
* A typed name at the end of an email
* A typed name on an electronic form or document
* An image of a handwritten signature on a transmitted fax
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