Allowing a proxy signer to generate a signature on behalf of an original signer, a proxy signature should satisfy the property of strong unforgeability: anyone except the designated proxy signer cannot create a valid proxy signature on behalf of the original signer. Since proxy signatures, as well as their derivatives, can be used in many applications in reality, such as secure mobile agent, e-...

Transport Layer Security (TLS) is commonly used to provide server-authenticated secure channels for HTTPS web applications. From the viewpoint of the client, however, the server authentication guarantees of HTTPS are frequently misconstrued to identify a single HTTPS endpoint or origin whereas, in practice, the HTTPS server may be serving any one of a large set of origins. This issue is even mo...

Undertaking foreign direct investment (FDI) is the defining feature of multinational enterprises (MNEs). While emerging economies as recipients of FDI are familiar with MNEs, these MNEs tend to be firms from the developed world. A new breed of home-grown MNEs has now arisen from the emerging economies, in particular the group known as BRIC (Brazil, Russia, India, and China). In this article, th...

In this paper we provide a new arithmetic characterization of the levels of the log-time hierarchy (LH). We define arithmetic classes Σ k and Π log k that correspond to Σk-LOGTIME and Πk-LOGTIME respectively. We break Σ k and Π log k into natural hierarchies of subclasses Σm·log k and Π m·log k . We then define bounded arithmetic deduction systems (TΣ k ) ′ whose U{|id|}B(Σ log k )-definable fu...

The philosophy underlying open source software (OSS) is enabling programmers to freely access the software source by distributing the software source code, thus allowing them to use the software for any purpose, to adapt and modify it, and redistribute the original or the modified source for further use, modification, and redistribution. The modifications, which include fixing bugs and improvin...

In some applications for synchronous stream ciphers, the risk of loss of synchroniration cannot be eliminated completely. In these cases frequent rcsynchroniration or resynduonisation upon request may be necessary. In the paper it is shown that this can lead to significant deterioration of the cryptographic security. A powerful general attack on nonlinearly filtered linear (over Z,) systems is ...

Recently a great deal of attention has been focused on quantum computation following a sequence of results [Bernstein and Vazirani, in Proc. 25th Annual ACM Symposium Theory Comput., 1993, pp. 11–20, SIAM J. Comput., 26 (1997), pp. 1411–1473], [Simon, in Proc. 35th Annual IEEE Symposium Foundations Comput. Sci., 1994, pp. 116–123, SIAM J. Comput., 26 (1997), pp. 1474–1483], [Shor, in Proc. 35th...