Bengaluru: When you enter your pin number in an ATM machine, or the details of your credit card onto a digital wallet like Paypal, you do so in the faith that your information will be kept completely confidential.

The Paypal account facilitates payments to other websites, while ensuring that your personal data is safe.

This study of secure communication is called cryptography, or cryptology and is a combination of three disciplines – mathematics, computer science and electrical engineering.

Silvio Micali, Ford Professor of Engineering, Massachussets Institute of Technology, is considered one of the revolutionaries of the subject.

Prof Micali delivered a lecture titled 'The Quest for Resilient Mechanism Design' at the Indian Institute of Science, in collaboration with the Infosys Science Foundation.

Prof. Micali is the recipient of the Turing Award (computer science), the Goedel Prize and the RSA prize. He is known for his work on pseudorandomness, interactive proofs and zero-knowledge proof that have revolutioned the understanding of cryptography.

"Mechanism design," said Prof. Micali, "is optimisation without information. All the information is with rational players, while the decision maker is ignorant.

He extracts logical data and chooses an outcome. The decision maker aspires to leverage information and rationality. The goal is allocation to the highest valuing player." He described an auction, where the bidder with the highest price wins.

Prof. Micali explained that 'collusion, complexity and privacy' are the three forces at play when it comes to sharing encrypted data.

Collusion is a secretive agreement made by two parties, which could be illegal, to deceive competition, like through wage fixing or kickbacks.

Complexity refers to something with many parts, with each part interacting with others in different ways. Privacy is the individual's ability to conceal information selectively.

This ties with security, because information that would otherwise have been concealed is put in the open, in the hope that it will be safeguarded.

“Mechanism design is based on the philosophy of truth as the dominant strategy," he said. It is a system where one party vouches for the authenticity of secret information provided by another.

"If everybody lies, then the revenue obtained will be zero," he said. "There are also many factors that affect the outcome, because the players are often irrational. The whole system, therefore, is bound by the tyranny of truth."