The IMU Abacus Medal is awarded once every 4 years at the International Congress of Mathematicians, for outstanding contributions in Mathematical Aspects of Information Sciences including: All mathematical aspects of computer science, including complexity theory, logic of programming languages, analysis of algorithms, cryptography, computer vision, pattern recognition, information processing and modelling of intelligence, scientific computing and numerical analysis, computational aspects of optimization and control theory, computer algebra. A candidate's 40th birthday must not occur before January 1st of the year of the Congress at which the Medal is awarded.