Xuejia Lai () is a cryptographer, currently a professor at

Shanghai Jiao Tong University Shanghai Jiao Tong University (SJTU; ) is a public research university in Shanghai, China. The university is funded by the Ministry of Education of China. The university was established on April 8, 1896 as Nanyang Public School (南洋� ...

. His notable work includes the design of the

block cipher In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called ''blocks''. Block ciphers are specified cryptographic primitive, elementary components in the design of many cryptographic protocols and ...

IDEA In common usage and in philosophy, ideas are the results of thought. Also in philosophy, ideas can also be mental representational images of some object. Many philosophers have considered ideas to be a fundamental ontological category of being ...

based on the Lai-Massey scheme, the theory of Markov ciphers, and the

cryptanalysis Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic sec ...

of a number of

cryptographic hash function A cryptographic hash function (CHF) is a hash algorithm (a map of an arbitrary binary string to a binary string with fixed size of n bits) that has special properties desirable for cryptography: * the probability of a particular n-bit output re ...

s. His book ''On the Design and Security of Block Ciphers'' () is frequently cited in cryptography papers. Lai received a

B.Sc. A Bachelor of Science (BS, BSc, SB, or ScB; from the Latin ') is a bachelor's degree awarded for programs that generally last three to five years. The first university to admit a student to the degree of Bachelor of Science was the University of ...

electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

in 1982 and an

M.Sc. A Master of Science ( la, Magisterii Scientiae; abbreviated MS, M.S., MSc, M.Sc., SM, S.M., ScM or Sc.M.) is a master's degree in the field of science awarded by universities in many countries or a person holding such a degree. In contrast to ...

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

in 1984 at

Xidian University Xidian University () is a public research university in Xi'an, Shaanxi, China, that is administered by the Ministry of Education of China. Xidian focuses on electronics and information education and research, and has programs covering enginee ...

(then known as ''Northwest Institute of Telecommunication Engineering''). About 1982 he met

James Massey James Lee Massey (February 11, 1934 – June 16, 2013) was an American information theorist and cryptographer, Professor Emeritus of Digital Technology at ETH Zurich. His notable work includes the application of the Berlekamp–Massey algorithm to ...

, who was visiting the university to give lectures in cryptography. Lai served as interpreter for these lectures. He later became one of Massey's doctoral students at

ETH Zurich (colloquially) , former_name = eidgenössische polytechnische Schule , image = ETHZ.JPG , image_size = , established = , type = Public , budget = CHF 1.896 billion (2021) , rector = Günther Dissertori , president = Joël Mesot , ac ...

, where he received his

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is ...

in 1992. Together they designed the IDEA cipher.

External links

Lai's bio at SJTU in Shanghai
(archived 2014)
Lai's faculty page at SJTU in Shanghai
Living people Chinese computer scientists Chinese cryptographers ETH Zurich alumni Modern cryptographers Shanghai Jiao Tong University faculty Year of birth missing (living people) {{crypto-bio-stub