digital signaturen. A digital file attached to an email or other electronic document that uses encryption and decryption algorithms to verify the document’s origin and contents.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.digital signature n (Computer Science) computing electronic proof of a person’s identity involving the use of encryption; used to authenticate documents Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014