Cryptographic Primitives for Mobile Networks (first part)
Yona Raekow (cosec - b-it)
Thursday 01July 2010, 15.00, b-it 1.25 (cosec meeting room)
Contents
This talk is the first part of a two-talk series that discusses the security of cryptographic primitives used in mobile communication systems such as UMTS, GSM, and GPRS. The focus of this talk is the block cipher KASUMI, that plays a vital role in the security of mobile telecommunications technologies.
We will first describe the architecture of cellular networks. Such networks are made up of a number of cells, each served by at least one base station. When joined together, these cells provide radio coverage over a wide geographic area. This enables a large number of portable transceivers to communicate with each other via base stations, even if some of the transceivers are moving through more than one cell during transmission.
Then, we will discuss the block cipher KASUMI in detail, as it was described in a 3GPP technical specification: KASUMI is a block cipher with 128-bit key and 64-bit input and output. The core of KASUMI is an eight-round Feistel network, which we will analyze during the talk.
The second part of the lecture will take place on July 15th and will discuss potential attacks on KASUMI as proposed by Orr Dunkelman, Nathan Keller, and Adi Shamir, as well as the consequences of these attacks.