Will a Rs 100 crore prize crack the Indus Valley script?

India's place in history as a cradle of ancient civilisation rests with the more than 5,000 year old Indus Valley Civilisation - comprising over 1,000 city/settlement sites stretching from the northwest to Gujarat. Astonishingly, we know very little about how this ancient society gained such sophisticated urban planning, hydraulic engineering, metallurgy and craftsmen skills - due in part to the yet undeciphered script.

The Indus Valley script comprises about 400 symbols (used both for meaning and phonetics), with a range of five to 26 symbols carved on embossed ceramic or clay "seals", often tied to a bundle of goods for trade. The tablets also displayed pictures of humans or animals, such as the Pashupati seal thought to be one of the earliest known representations of Shiva or Rudra. Over 4,000 examples of Indus Valley script have been found, including the intriguing Dholavira Signboard, a large wooden board with ten symbols at the entrance to a magnificent Indus Valley citadel in the Kutch district of Gujarat.

Over the last hundred years, there have been many attempts to decipher the script but no one has cracked it yet. Noted Indologists, such as Iravatham Mahadevan, Krishna Rao and Asko Parpola, suggest the Indus script is a predecessor of the Bramhi script but other Western scholars think these are just simple non-linguistic emblems rather than an actual written language. Even the direction of the writing, thought to be from right to left, remains uncertain.

The traditional way to decipher a lost language was to either find a bilingual artifact, such as the famous Rosetta Stone which had three scripts and was used to decipher Egyptian hieroglyphics. Even then, it took several decades since the discovery of the Rosetta Stone for full translation of the Egyptian hieroglyphics. Some languages have been decoded by amateurs after archeologists gave up. Michael Ventris, an architect, used his spare time to decipher the puzzle of Linear B (the oldest Greek script) and in doing so showed that the prior leading archeological theory of Linear B was wrong!

The Indus Valley script has now eluded traditional methods for close to a century. At present, Indus Valley seals are held in museums and private collections across the world. Individual efforts to centralise this trove will likely never stay up to date due to new discoveries and missing pieces. However, the advent of powerful computational tools and internet-based crowdsourcing has opened up new possibilities.

Recently, Rajesh Rao's group at Washington University used artificial intelligence (AI) to compare several known natural linguistic systems (eg Old Tamil, Rig Vedic Sanskrit, English), with non-linguistic systems (eg human DNA sequences) and an artificial language used in computer programming (FORTRAN). They found that the conditional entropy (a degree of randomness) of the Indus script fell between that of English alphabet and Old Tamil - providing support for the Indus script as a language. Mayank Vahia, an astrophysicist at TIFR, analysed 1548 lines of Indus Valley data and finds that the unit length of information is two, three or four signs at a time.

While these discoveries are commendable, many unanswered questions remain. We suggest a three-pronged strategy to substantially accelerate progress:

1) Create a global public digital repository of all Indus Valley scripts, which anyone can contribute to and analyse (modelled on The Rosetta Project);

2) Create a prize for cracking the code (like the $15 million donor funded X prize for learning or through a crowdsourced Kickstarter campaign);

3) Publicise to attract teams who may not have heard of the problem but have diverse skills beyond linguistics and archaeology (such as pattern recognition or computational neuroscience). Then, perhaps even IBM's Watson (a cognitive supercomputer) would take on the challenge.

The impact of understanding ancient languages is powerful both emotionally and scientifically. The Rosetta stone is the most visited object at the British Museum today. Decoding the ancient Hittite script (modern day Turkey) established this hitherto unknown empire as a powerful force in the Middle East, rivalling the Egyptian and Babylonian kingdoms. The Indus Valley script is an embodiment of our identity and culture - deciphering it could not only further cement India's rich ancient heritage but may inspire solutions to other large societal and scientific challenges.