@misc{cryptoeprint:2021:1050,
author = {Sara Ricci and
Petr Dzurenda and
Jan Hajny and
Lukas Malina},
title = {Privacy-Enhancing Group Signcryption Scheme},
howpublished = {Cryptology ePrint Archive, Report 2021/1050},
year = {2021},
note = {\url{https://ia.cr/2021/1050}},
}
You will need the url.sty package (comes with most LaTeX installations) for the last line. Otherwise, remove the \url command.