What is the main reason that the indus script has not yet been deciphered? story if you need it: “slightly over 400 basic signs have been identified as part of the indus script. only 31 of these signs occur over 100 times, while the rest were not used regularly. this leads researchers to believe that a large amount of the indus script was actually written on perishable materials, such as palm leaves or birch, which did not survive the destruction of time. this is hardly surprising considering that palm leaves, birch and bamboo tubes were widely used as writing surfaces in south and south east asia. some researchers have argued that the roughly 400 symbols can actually be reduced to 39 elementary signs, the rest being merely variations of styles and differences between scribes. there are a number of factors preventing scholars from unlocking the mystery of the indus script. to begin with, some of the languages of ancient times, such as egyptian, were deciphered to the recovery of bilingual inscriptions, that is by comparing an unknown script with a known one. unfortunately, no bilingual inscriptions have yet been found to allow the indus script to be compared to a known writing system. another obstacle for its decipherment relates to the fact that all of the inscriptions found so far are relatively short, fewer than 30 signs. this means that analyzing recurring sign patterns, another technique that can to unlock the meaning of a writing system, cannot be successfully performed for the indus script. the last important reason why the indus script remains undeciphered, and possibly the most debated of all, is that the language (or languages) that the script represents is still unknown. scholars have suggested a number of possibilities: indo-european and dravidian are the two language families most commonly favored, but other options have been proposed as well, such as austroasiatic, sino-tibetan, or perhaps a language family that has been lost. on the basis of the material culture associated with the indus valley civilization, a number of scholars have suggested that this civilization was not indo-european.”