SNOW 3G is a stream cipher used as one of the standard algorithms for data confidentiality and integrity protection over the air interface in the 3G and 4G mobile communication systems. SNOW-V is a recent new version that was proposed as a candidate for inclusion in the 5G standard. In this paper, we propose a faster variant of SNOW-V, called SNOW-Vi, that can reach the targeted speeds for 5G in a software implementation on a larger variety of CPU architectures. SNOW-Vi differs in the way how the LFSR is updated and also introduces a new location of the tap T2 for stronger security, while everything else is kept the same as in SNOW-V. The throughput in a software environment is increased by around 50% in average, up to 92 Gbps. This makes the applicability of the cipher much wider and more use cases are covered. The security analyses previously done for SNOW-V are not affected in most aspects, and SNOW-Vi provides the same 256-bit security level as SNOW-V.

We present MProsper, a trustworthy system to prevent code injection in Linux on embedded devices. MProsper is a formally verified run-time monitor, which forces an untrusted Linux to obey the executable space protection policy; a memory area can be either executable or writable, but cannot be both. The executable space protection allows the MProsper’s monitor to intercept every change to the executable code performed by a user application or by the Linux kernel. On top of this infrastructure, we use standard code signing to prevent code injection. MProsper is deployed on top of the Prosper hypervisor and is implemented as an isolated guest. Thus MProsper inherits the security property verified for the hypervisor: (i) Its code and data cannot be tampered by the untrusted Linux guest and (ii) all changes to the memory layout is intercepted, thus enabling MProsper to completely mediate every operation that can violate the desired security property. The verification of the monitor has been performed using the HOL4 theorem prover and by extending the existing formal model of the hypervisor with the formal specification of the high level model of the monitor. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

A5/1 is a stream cipher used in the Global System for Mobile Communications (GSM) standard. Several time-memory tradeoff attacks against A5/1 have been proposed, most notably the attack by Biryukov, Shamir and Wagner (1978), which can break A5/1 in seconds using huge precomputation time and memory. This article presents a completely different attack on A5/1, based on ideas from correlation attacks. Whereas time-memory tradeoff attacks have a complexity which is exponential with the shift-register length, the complexity of the proposed attack is almost independent of the shift-register length. Our implementation of the suggested attack breaks A5/1 in a few minutes using 2-5 min of conversation plaintext.