Dual security

The fail-stop property is stronger than both these types One can simulate ordinary security by identifying broken with TRUE and dual security by identifying broken with FALSE. 

Dual security is dual to ordinary security The requirement of the signer on disputes is fulfilled information-theoretically, that of the recipient computationally only, and there is no fail-stop property. If transferability is required, the effectiveness of transfers need only hold computationally. 

As sketched after Figure 5.13, schemes with fail-stop security can be used as schemes with either ordinary or dual security, if one identifies the output broken with TRUE or FALSE, respectively, i.e., if one assigns the responsibility for authenticated messages either always to the signer or always to the recipient even if the scheme has been broken. 

With dual security, the signer can only be secure with an error probability. 

Invisible Signature Schemes with Dual Security... 

It is not hard to imagine that a scheme with information-theoretic security would greatly increase the legal security of digital signatures. However, as mentioned in Section 6.1.5, such schemes are currently impractical and it seems that they will never be very efficient. Hence their social implications are not very relevant. In contrast, practical schemes with fail-stop or dual security exist. Hence the only two topics of this section are... 

To rule out misunderstanding The claim in the first topic is not dual security is better than ordinary security . 

Possible BeneHts of Dual Security Use in Message Exchange... 

The possible benefits of a fail-stop signature scheme used as a dual signature scheme have already been discussed in Section 6.2.1. Hence this section concentrates on the advantages of fail-stop security that cannot be achieved by a combination of schemes with ordinary and dual security. 

As mentioned in Section 6.1.4, the usual method to obtain a non-invisible signature scheme with dual security is to use a fail-stop signature scheme and to identify broken with FALSE. The properties of the only other existing scheme of this type were sketched there, too. 

Note that only dual security has been achieved, and not a fail-stop property The court s entity cannot distinguish the situation where an attacker shows a random number s, claiming it were an invisible signature, and the signer disavows s , from the situation where the cryptologic assumption has been broken. Hence the court s result is acc = FALSE in both cases, never acc = broken . 

Lighting need not be devoted to security, and indeed most lighting installations have a dual role. Where security is a required feature, the installation needs to be very carefully specified and designed to achieve optimum protection. 

To combat attacks with fast-acting agents in the terminals, continuous visual surveillance of densely populated areas and observation of behavior patterns may be as useful as any detector. The TSA should study the feasibility of the widespread deployment of surveillance cameras in populated areas, coupled with behavioral-pattern-recognition software, as an alternative to chemical agent detectors. Such cameras could also provide a dual-use value in improving the overall security environment. In addition, many critical nodes in the air transportation system (control rooms, emergency-response centers, and so on) are supplied with air that is recirculated from publicly accessible areas this makes them vulnerable to being disabled by the release of... 

F. L. Roder, Preliminary feasibihty investigation — explosives detection by dual-energy computerized tomography, The Aerospace Corporation, El Segundo, CA, ATR-78(3860-06)-IND. Security Intelligence Report, Micro-dose finds objects under clothes, 11 March (1991) 3. Aviation Week Space Technology, Personnel scanner, 10 June (1991) 11. 

W.F. Aitkenhead and J.H. StiUson, Dual-energy x-ray Compton scattering measurement as a method to detect sheet explosive, in Proc. 2nd Explosives Detection Symposium Aviation Security Conference, W.H. Makky (ed.) 12-14 November 1996, Adantic City, NJ, FAA (1996) 236-247. 

DoD, then, is a minor customer in a specialized niche market of minimal commercial interest. The needs of homeland security may expand the potential for a dual-use military and civilian market, but that has yet to occur. Public-sector financing may be required, therefore, to a greater extent in the development of CBW drugs and vaccines than for general military health needs. 

The more secure new rooting of the eukaryotic tree (Fig. 8.1) is between bikonts, which almost certainly ancestrally had tubular mitochondrial cristae, and unikonts, which comprise the Amoebozoa with tubular cristae and opisthokonts with flat cristae (Richards and Cavalier-Smith 2005 Stechmann and Cavalier Smith 2003). The cenancestral eukaryote probably therefore had tubular mitochondrial cristae. The majority of photosynthetic a-proteobacteria have tubular chromatophores, which carry the dual... 

The dual objectives of downsizing the FSU weapons complexes and preventing the diversion of expertise may present greater proliferation dangers in the short run, but lower the danger over time as the complexes diminish in size. While smaller weapons complexes are more likely to receive consistent financial support and make it easier to ensure security, the downsizing process may create short-term instability at certain facilities and thereby raise the risk of personnel diverting their expertise. 

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