Mohib, Wikipedia has a good definition of the term digital signature. It is not a USB drive. It can certainly be contained on one. https://en.wikipedia.org/wiki/Digital_signature
You can use a digital signature to sign electronic documents such as contracts. I understand that it is accepted by Indian law but I do not know how prevalent signing contracts this way is in India. Pranav Register at the dedicated AccessIndia list for discussing accessibility of mobile phones / Tabs on: http://mail.accessindia.org.in/mailman/listinfo/mobile.accessindia_accessindia.org.in Search for old postings at: http://www.mail-archive.com/accessindia@accessindia.org.in/ To unsubscribe send a message to accessindia-requ...@accessindia.org.in with the subject unsubscribe. To change your subscription to digest mode or make any other changes, please visit the list home page at http://accessindia.org.in/mailman/listinfo/accessindia_accessindia.org.in Disclaimer: 1. Contents of the mails, factual, or otherwise, reflect the thinking of the person sending the mail and AI in no way relates itself to its veracity; 2. AI cannot be held liable for any commission/omission based on the mails sent through this mailing list..