This documentation applies for JabRef 4.1 or later.
The International Association for Cryptologic Research maintains an eprint archive to which anyone can submit papers and technical reports. These eprints are given IDs based on the year of submission, e.g. the 10th submission in 2018 gets the ID “2018/10”.
To create a new entry form an IACR eprint ID, choose BibTeX → New entry…. In the lower part, there is the box “ID-based entry generator”. In the field “ID type”, “IACR” should be already selected. The field “ID” is focused. Enter the eprints’ ID here and press Enter to generate an entry based on the Id. You can also click on “Generate”. The new entry is opened in an entry editor. In case an error occurs, a popup is shown.
To get the ID, you may want to use their web search form at https://eprint.iacr.org/search.html.