In December 2015, two researchers from Aarhus University published a report in which they demonstrated that MTProto does not achieve indistinguishability under chosen-ciphertext attack (IND-CCA) or authenticated encryption.
I december 2015 publicerade två forskare på Århus Universitet en rapport i vilket de kunde demonstrera att MTProto inte når upp till Ciphertext indistinguishability#Indistinguishability under chosen ciphertext attack (IND-CCA) eller authenticated encryption.