This is one detailed survey: https://eprint.iacr.org/2021/1402.pdf https://eprint.iacr.org/2021/1402.pdf The underlying cryptosystems are often LWE (Learning w

This is one detailed survey: https://eprint.iacr.org/2021/1402.pdf https://eprint.iacr.org/2021/1402.pdf The underlying cryptosystems are often LWE (Learning with Errors), RLWE (Ring Learning with Errors) and one called (R)GSW (named after the authors of this paper: https://eprint.iacr.org/2013/340 https://eprint.iacr.org/2013/340) which is also based on (R)LWE.