Video from 2011.
"Four-thousand years ago, an urban civilization lived and traded on what is now the border between Pakistan and India. During the past century, thousands of artifacts bearing hieroglyphics left by this prehistoric people have been discovered. Today, a team of Indian and American researchers are using mathematics and computer science to try to piece together information about the still-unknown script." Source: Science Daily (2009).
Video from 2015. I'm not sure how accurate some of this is.
Note: "The Indus script (also known as the Harappan script) is a corpus of symbols produced by the Indus Valley Civilisation during the Kot Diji and Mature Harappan periods between 3500 and 1900 BCE. Most inscriptions containing these symbols are extremely short, making it difficult to judge whether or not these symbols constituted a script used to record a language, or even symbolise a writing system. In spite of many attempts, ‘the script’ has not yet been deciphered, but efforts are ongoing. There is no known bilingual inscription to help decipher the script, and the script shows no significant changes over time. However, some of the syntax (if that is what it may be termed) varies depending upon location." (Wikipedia)
More information: The Indus Script entry at Ancient Scripts.