Chris Peikert
American cryptographer at the University of Michigan who helped make lattice cryptography efficient enough to standardise.
Regev's LWE problem from 2005 was elegant but produced large keys. In 2010 Peikert, Vadim Lyubashevsky and Oded Regev introduced Ring-LWE, using the structure of polynomial rings to shrink keys dramatically without losing the security reduction. That idea, and the module variant that followed, sits underneath ML-KEM and ML-DSA in NIST's post-quantum standards.
With Craig Gentry and Vinod Vaikuntanathan he also wrote the GPV paper (2008) on lattice trapdoors, which made lattice-based signatures and identity-based encryption practical. His survey A Decade of Lattice Cryptography (2016) is a common way into the field.