The A5/1 encryption cypher fell last week and now the A5/3 has been cracked.
Not a good week for mobile phone carriers and alarm bells should be ringing if you are planning involving the GSM association in any secure applications and perhaps you need to revisit the risk equation.
For those in the know a new type of attack was used to construct a simple distinguisher for 7 of the 8 rounds of KASUMI with exceptionally high probability. The distinguisher provides the opportunity for analyzing the single remaining round enabling derivation
of the 128 bit key of the full KASUMI by using only 4 related keys, 226 data, 230 bytes of memory, and 232 time. This translatesa into a couple of hours on a standard PC.
MISTY the old crypto was in fact harder to break. The GSM crew made a backward step of a very high order. (the limitations of the type in this blog prevent me from providing more specific information).
Not the sort of progress I like to make.
The bottom line is that your mobile phone may as well be a CB radio.