Anti-Carboxypeptidase Y (C-terminal) polyclonal antibody [Biotin]

We propose extensions to the Dolev-Yao attacker model to make it suitable for arguments about security of Cyber-Physical Systems. The Dolev-Yao attacker model uses a set of rules to define potential actions by an attacker with respect to messages (i.e. information) exchanged between parties during a protocol execution. As the traditional Dolev-Yao model considers only information (exchanged over a channel controlled by the attacker), the model cannot directly be used to argue about the security of cyber-physical systems where physical-layer interactions are possible. Our Dolev-Yao extension, called Cyber-Physical Dolev-Yao (CPDY), allows additional orthogonal interaction channels between the parties. In particular, such orthogonal channels can be used to model physical-layer mechanical, chemical, or electrical interactions between components. In addition, we discuss the inclusion of physical properties such as location or distance in the rule set. We present an example set of additional rules for the Dolev-Yao attacker, using those we are able to formally discover physical attacks that previously could only be found by empirical methods or detailed physical process models.

The effects of high pressure, up to 400 MPa, on the catalytic activity and the CPDY showed a pH-dependent Suc-Ala-Ala-Pro-Phe-pNA hydrolysis similar to other neutral substrates. The apparent second-order rate showed a gradual decrease with increasing pressure, which was related to an increase in K-m and a decrease in k(cat). The intrinsic fluorescence of CPDY showed a gradual decrease in the intensity and a red shift in the maximum wavelength with pressure. The transition curve did not follow a simple tow-state transition, but contained at least three states. The first transition occurred at around 100 MPa and the second one occurred at pressures higher than 200 MPa. After incubation at 300 MPa, both the peak intensity and the maximum wavelength did not show complete restoration; the pressure-induced change is substantially irreversible. The latter change corresponds to the increased binding of a fluorescent hydrophobic probe molecule (8-anilino-1-naphthalenesulfonic acid) to this protein; however, the CD spectrum showed practically no evidence of irreversible changes in the protein's secondary structure.