Backdoor

Cavalli-Sforza, L.L., Genes, Peoples, and Languages. New York Northpoint Press (2000). Duster, T., Backdoor to Eugenics. New York Rutledge (1990). 

Some SCADA systems use unique, proprietary protocols for communications between field devices and servers. Often the security of SCADA systems is based solely on the secrecy of these protocols. Unfortunately, obscure protocols provide very little real security. Do not rely on proprietary protocols or factor default configuration settings to protect your system. Additionally, demand that vendors disclose any backdoor or vendor interfaces to your SCADA systems, and expect them to provide systems that are capable of being secured. 

Establish strong controls over any medium that is used as a backdoor into the SCADA network. 

Where backdoor or vendor connections do exist in SCADA systems, strong authentication must be implemented to ensure secure communications. Modems, wireless, and wired networks used for communications and maintenance represent a significant vulnerability to the SCADA network and remote sites. Successful war dialing or war driving attacks could allow an attacker to bypass all other controls and have direct access to the SCADA network or resources. To minimize the risk of such attacks, disable inbound access and replace it with some type of callback system. 

Gun rights advocates, however, see such efforts as an attempt to stretch reasonable concepts of liability into a form of backdoor gun control, in effect obtaining through the courts what they could not obtain through political means. They argue that if such suits are widely successful, gun manufacturers may be forced out of business, or at least forced to market only expensive handguns, affordable only by the well-off and by criminals. Thus, in a law journal article, Philip D. Oliver warns that... 

If a question stumps you, try one of the backdoor approaches explained in the next section. These are particularly useful for solving word problems. 

Backdoor Approaches for Answering Questions That Puzzle You... 

Remember those word problems you dreaded in high school Many of them are actually easier to solve by backdoor approaches. The two techniques that follow are terrific ways to solve multiple-choice word problems that you don t know how to solve with a straightforward approach. The first technique, nice numbers, is useful when there are unknowns (like x) in the text of the word problem, making the problem too abstract for you. The second technique, working backward, presents a quick way to substitute numeric answer choices back into the problem to see which one works. 

Figure 17. Analysis of phosphoenzyme intermediates of SR Ca2+-ATPase mutants with alterations to carboxylate-containing residues in the transmembrane sector. Wild-type or mutant Ca2+-ATPases expressed in the endoplasmic reticulum membranes of COS-1 cells were phosphorylated with [y-32P] ATP (panel a) or [32P]P (panels b and c). Following acid-quench of the phosphorylated intermediate, the samples were subjected to SDS-polyacrylamide gel electrophoresis under acid pH conditions and the dried gels were autoradiographed to visualize the radioactivity associated with the covalently bound phosphate. Panel a shows the Ca2+-concentration dependence of phosphorylation from ATP. The Glu309- Lys mutant is unable to phosphorylate, even at 12.5 mM Ca2+. In the wild-type Ca2+-ATPase the phosphorylation reaction is fully saturated at 10 pM Ca2+. Panel b shows lack of Ca2+ inhibition of backdoor phosphorylation from P in the mutants. E indicates the presence of ECTA to chelate Ca2+ (normally a requirement for phosphorylation by the backdoor route). C indicates the...

Figure 22. Analysis of the rates of dephosphorylation of phosphoenzyme intermediates of wild-type and Pro312 mutants of the SR Ca2+-ATPase. Left panel Phosphorylation was performed with [y-32P]ATP in the presence of Ca2+. The buffer conditions were adjusted to obtain predominantly E,P in steady state as indicated by the complete disappearance of the phosphoenzyme upon addition of ADP. EGTA was added to terminate phosphorylation by chelation of Ca2+ and permit observation of the dephosphorylation of E,P through conversion to E2Pand hydrolysis of the latter intermediate. A rapid dephosphorylation is observed with the wild type, while in the mutants the dephosphorylation of E,P is inhibited. More than 80% of the phosphoenzyme remains five minutes after addition of EGTA in the Pro312- Ala mutant. Right panel Phosphorylation was performed with [32P]Pj by the backdoor reaction in the absence of Ca2+...

The pre-op crew steamed out the B Unit first and vented it through the 8-inch steam vent piping. The failure occurred about four days later. An eyewitness in the operators shelter heard what sounded like a muffled explosion and ran out the backdoor to. see if he could locate fire or smoke. Fortunately, no fire could be seen, but the collapsed coker drum was very visible. 

Make a plan of attack to help you solve the problem. If a question stumps you, try one of the backdoor approaches explained in the next section. These are particularly useful for solving word problems. When you get yoiu" answer, reread the circled question to make siu e you have answered it. This helps avoid the careless mistake of answering the wrong question. 

BACKDOOR APPROACHES FOR ANSWERING QUESTIONS THAT PUZZLE YOU... 

Coupled to the folding of the myosin molecule is a change at the active site that results in "trapping" of nucleotide (Cross et al., 1986). The observed rate of phosphate release from single-turnover experiments, <0.0005 sec i, likely reflects product release from the small amount of extended myosin that is in equilibrium with the folded monomer (Cross et al., 1988). The structural basis for trapping is not known. It has been proposed that after MgATP is cleaved at the active site, phosphate leaves via a "backdoor" mechanism (Yount et al., 1995). Perhaps in the folded monomer the glycine-rich P-loop is stabilized in a conformation that prevents phosphate release. 

The cover image is a barrel shot of a professional surfer at Backdoor, Oahu. 

C. Kurtsiefer, P. Zarda, S. Mayer, H. Weinlurter, The breakdown flash of Silicon Avalance Photodiodes - backdoor for eavesdropper attacks , J. Mod. Opt. 48, 2039-2047 (2001)... 

Fig. 2.4 In multireference Rayleigh-Schrodinger perturbation theory, states from outside the reference space, V, which assume an energy below that of any state among the reference set for — 1 < A < 0 are termed backdoor intruder states. Unlike the intruder states corresponding to 0 < X < +1, which often have a physical origin, backdoor intruder states are frequently unphysical...

All NAC architectures suffer from the lack of support for network devices such as printers, smartphones (Blackberry, iPhone, etc) and enterprise robots. In addition, fake NAC agent software can be used to b3q)ass the integrity checks for cHent machines. (Thu-mann Roecher 2007) Additional vulnerabihties in TNC due to its support of TPM are possibility to contain a backdoor at the TPM allowing access by unauthorized parties and data loss due to the damage of TPM hardware. 

R. M. Kidder, Chemical Weapons at NATO s backdoor . The Christian Science Monitor, 13 December 1979, p. 1 and J. Erickson, The Soviet Union s Growing Arsenal , p. 65. 

In pathologic states in which 170HP accnmu-lates, 19-carbon steroid production can follow an alternate or backdoor pathway if 5a-reductase is present [39], as in the neonatal tammar wallaby testis [40]. In this pathway, 170HPimdergoes5a-and 3a-reduction to 5a-pregnane-3a,17a-diol-... 

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