One-time signatures (OTS) are called one-time, because the accompanying reductions only guarantee security under single-message attacks. However, this does not imply that efficient attacks are possible under two-message attacks. Especially in the context of hash-based OTS (which are basic building blocks of recent standardization proposals) this leads to the question if accidental reuse of a on...

This study examines the possibility of groundbased remote-sensing ozone total column amounts (OTC) from spectral signatures at 3040 and 4030 cm−1. These spectral regions are routinely measured by the NDACC (Network for the Detection of Atmospheric Composition Change) ground-based FTIR (Fourier transform infraRed) experiments. In addition, they are potentially detectable by the TCCON (Total Carb...

Proxy signatures are very useful tools when one needs to delegate his/her signing capability to other party. After Mambo et al.’s first scheme was announced, many proxy signature schemes and various types of proxy signature schemes have been proposed. Due to the various applications of the bilinear pairings in cryptography, there are many IDbased signature schemes have been proposed. In this pa...

Symplectic geometry is an even dimensional geometry. It lives on even dimensional spaces, and measures the sizes of 2-dimensional objects rather than the 1-dimensional lengths and angles that are familiar from Euclidean and Riemannian geometry. It is naturally associated with the field of complex rather than real numbers. However, it is not as rigid as complex geometry: one of its most intrigui...

We prove that if one can predict any of the bits of the input to an elliptic curve based one-way function over a finite field, then we can invert the function. In particular, our result implies that if one can predict any of the bits of the input to a classical pairing-based one-way function with non-negligible advantage over a random guess then one can efficiently invert this function and thus...

In order to circumvent the influence of correlation in paired-samples and repeated measures experimental designs, researchers typically perform a one-sample Student t test on difference scores. That procedure entails some loss of power, because it employs N – 1 degrees of freedom instead of the 2N – 2 degrees of freedom of the independent-samples t test. In the case of non-normal distributions,...

As for the problem that ElGamal digital signature scheme’s security is constantly being challenged and increasingly becomes increasingly serious, an improved ElGamal digital signature algorithm is proposed. As the original ElGamal algorithm has its own security disadvantages that only one random number is used, in order to improve its security, the scheme presented in this paper improved this d...

Proxy signatures are very useful tools when one needs to delegate his/her signing capability to other party. After Mambo et al.’s first scheme was announced, many proxy signature schemes and various types of proxy signature schemes have been proposed. Due to the various applications of the bilinear pairings in cryptography, there are many IDbased signature schemes have been proposed. In this pa...