104,335 research outputs found
Unified Description for Network Information Hiding Methods
Until now hiding methods in network steganography have been described in
arbitrary ways, making them difficult to compare. For instance, some
publications describe classical channel characteristics, such as robustness and
bandwidth, while others describe the embedding of hidden information. We
introduce the first unified description of hiding methods in network
steganography. Our description method is based on a comprehensive analysis of
the existing publications in the domain. When our description method is applied
by the research community, future publications will be easier to categorize,
compare and extend. Our method can also serve as a basis to evaluate the
novelty of hiding methods proposed in the future.Comment: 24 pages, 7 figures, 1 table; currently under revie
Execution Integrity with In-Place Encryption
Instruction set randomization (ISR) was initially proposed with the main goal
of countering code-injection attacks. However, ISR seems to have lost its
appeal since code-injection attacks became less attractive because protection
mechanisms such as data execution prevention (DEP) as well as code-reuse
attacks became more prevalent.
In this paper, we show that ISR can be extended to also protect against
code-reuse attacks while at the same time offering security guarantees similar
to those of software diversity, control-flow integrity, and information hiding.
We present Scylla, a scheme that deploys a new technique for in-place code
encryption to hide the code layout of a randomized binary, and restricts the
control flow to a benign execution path. This allows us to i) implicitly
restrict control-flow targets to basic block entries without requiring the
extraction of a control-flow graph, ii) achieve execution integrity within
legitimate basic blocks, and iii) hide the underlying code layout under
malicious read access to the program. Our analysis demonstrates that Scylla is
capable of preventing state-of-the-art attacks such as just-in-time
return-oriented programming (JIT-ROP) and crash-resistant oriented programming
(CROP). We extensively evaluate our prototype implementation of Scylla and show
feasible performance overhead. We also provide details on how this overhead can
be significantly reduced with dedicated hardware support
Shining Light On Shadow Stacks
Control-Flow Hijacking attacks are the dominant attack vector against C/C++
programs. Control-Flow Integrity (CFI) solutions mitigate these attacks on the
forward edge,i.e., indirect calls through function pointers and virtual calls.
Protecting the backward edge is left to stack canaries, which are easily
bypassed through information leaks. Shadow Stacks are a fully precise mechanism
for protecting backwards edges, and should be deployed with CFI mitigations. We
present a comprehensive analysis of all possible shadow stack mechanisms along
three axes: performance, compatibility, and security. For performance
comparisons we use SPEC CPU2006, while security and compatibility are
qualitatively analyzed. Based on our study, we renew calls for a shadow stack
design that leverages a dedicated register, resulting in low performance
overhead, and minimal memory overhead, but sacrifices compatibility. We present
case studies of our implementation of such a design, Shadesmar, on Phoronix and
Apache to demonstrate the feasibility of dedicating a general purpose register
to a security monitor on modern architectures, and the deployability of
Shadesmar. Our comprehensive analysis, including detailed case studies for our
novel design, allows compiler designers and practitioners to select the correct
shadow stack design for different usage scenarios.Comment: To Appear in IEEE Security and Privacy 201
WEB service interfaces for inter-organisational business processes an infrastructure for automated reconciliation
For the majority of front-end e-business systems, the assumption of a coherent and homogeneous set of interfaces is highly unrealistic. Problems start in the back-end, with systems characterised by a heterogeneous mix of applications and business processes. Integration can be complex and expensive, as systems evolve more in accordance with business needs than with technical architectures. E-business systems are faced with the challenge to give a coherent image of a diversified reality. Web services make business interfaces more efficient, but effectiveness is a business requirement of at least comparable importance. We propose a technique for automatic reconciliation of the Web service interfaces involved in inter-organisational business processes. The working assumption is that the Web service front-end of each company is represented by a set of WSDL and WSCL interfaces. The result of our reconciliation method is a common interface that all the parties can effectively enforce. Indications are also given on ways to adapt individual interfaces to the common one. The technique was embodied in a prototype that we also present
- …