I misspoke in saying "receipt". You're right that we can't rely on voters keeping their receipts for a recount. I meant a paper record of the vote kept in addition to the electronic record.
I'm not sure where I might have given the impression that a recount would not be necessary. A paper record makes a recount possible and the election system auditable.
The linked Wikipedia article on end-to-end auditable voting systems provides an overview and links to different methods of making voting systems more trustworthy. There's a lot of thought and details that go into it, and if it's something you're interested in, I suggest following up on some of the links and spending more time. I know it's taken me reading a lot of different articles and implementations, and I still need to look up different parts of it.
I did find this slide deck from Ron Rivest helpful:
"Auditability and Verifiability of Elections"
ACM-IEEE talk March 16, 2016
I'm not sure where I might have given the impression that a recount would not be necessary. A paper record makes a recount possible and the election system auditable.
The linked Wikipedia article on end-to-end auditable voting systems provides an overview and links to different methods of making voting systems more trustworthy. There's a lot of thought and details that go into it, and if it's something you're interested in, I suggest following up on some of the links and spending more time. I know it's taken me reading a lot of different articles and implementations, and I still need to look up different parts of it.
I did find this slide deck from Ron Rivest helpful:
"Auditability and Verifiability of Elections" ACM-IEEE talk March 16, 2016
https://people.csail.mit.edu/rivest/pubs/Riv16x.pdf
Were there particular areas that didn't make sense to you?