The New York Times today features an article by Pragati K.B. titled Want a Million Dollars? Get Busy Deciphering This Ancient Script. (non-paywall link).
It is a riddle that has confounded scholars for over a century. And now it carries a handsome cash prize: $1 million for anyone who can decipher the script of the ancient Indus Valley civilization. [...]
Since the Archaeological Survey of India announced the first findings on the civilization in 1924, around 5,000 inscriptions have been excavated.
They are engraved in stone or metal, or stamped onto fired clay. The brevity of the inscriptions, along with the absence of a Rosetta Stone-like text showing its symbols in translation, are among the reasons the script has not been deciphered, scholars say. [...]
There is some political motivation for the new prize, but what I found more interesting is the background and the reason for the puzzle still unsolved (no Rosetta stone), which the article explains.
There's a Wikipedia page about Indus script with some examples, and the collection mentioned in the newspaper article can be found on archive.org (large .pdf with lots of images!).
What could the symbols on those seals mean? Family names? What's your theory?