RSA Generation Research Articles

Practical RSA signature scheme based on periodical rekeying for wireless sensor networks

Broadcast is an efficient communication channel on wireless sensor networks. Through authentic broadcast, deployed sensors can perform legitimate actions issued by a base station. According to previous literature, a complete solution for authentic broadcast is digital signature based on asymmetric cryptography. However, asymmetric cryptography utilizes expensive operations, which result in computational bottlenecks. Among these cryptosystems, Elliptic Curve Cryptography (ECC) seems to be the most efficient and the most popular choice. Unfortunately, signature verification in ECC is not efficient enough. In this article, we propose an authentic broadcast scheme based on RSA. Unlike conventional approaches, the proposed scheme adopts short moduli to enhance performance. Meanwhile, the weakness of short moduli can be fixed with rekeying strategies. To minimize the rekeying overhead, a Multi-Modulus RSA generation algorithm, which can reduce communication overhead by 50%, is proposed. We implemented the proposed scheme on MICAz. On 512-bit moduli, each verification spends at most 0.077 seconds, which is highly competitive with other public-key cryptosystems.

Pseudorandom sequences constructed by the power generator

We study the pseudorandom properties of the power generator (which includes as special cases the RSA generator and the Blum--Blum--Shub generator). In order to estimate the pseudorandom measures character sums with exponential functions are used.

On the Linear Complexity of the Power Generator

We obtain a lower bound on the linear complexity of the power generator of pseudo-random numbers, which in some special cases is also known as the RSA generator and as the Blum–Blum–Shub generator. In some very important cases this bound is essentially the best possible. In particular, this implies that lattice reduction attacks on such generators are not feasible.

On the distribution of the power generator

We present a new method to study the power generator of pseudorandom numbers modulo a Blum integer m m . This includes as special cases the RSA generator and the Blum–Blum–Shub generator. We prove the uniform distribution of these, provided that the period t ≥ m 3 / 4 + δ t\ge m^{3/4 + \delta } with fixed δ > 0 \delta > 0 and, under the same condition, the uniform distribution of a positive proportion of the leftmost and rightmost bits. This sharpens and generalizes previous results which dealt with the RSA generator, provided the period t ≥ m 23 / 24 + δ t\ge m^{23/24 + \delta } . We apply our results to deduce that the period of the binary sequence of the rightmost bit has exponential length.

Inhibition by 8-hydroxy-2-(di-n-propylamino) tetralin and SM-3997, a novel anxiolytic drug, of the hippocampal rhythmical slow activity mediated by 5-hydroxytryptamine1A receptors

Electrophysiological studies using spectral analysis techniques were undertaken in rabbits to determine whether or not hippocampal rhythmical slow activity (RSA, theta wave activity) was affected by the 5-hydroxy-tryptamine1A (5-HT1A) agonists 8-hydroxy-2-(di-n-propyl-amino) tetralin (8-OH-DPAT) and 3a alpha, 4 beta, 7 beta, 7a alpha-hexahydro-2-(4-(4-(2-pyrimidinyl)-1-piperazinyl)-butyl)-4, 7-methano-1H-isoindole-1,3(2H)-dione dihydrogen citrate (SM-3997, a newly synthesized anxiolytic drug). Intravenous administration of 8-OH-DPAT and SM-3997 induced a desynchronized pattern with low-amplitude slow wave activity in the hippocampal EEG and inhibited RSA generation following stimulation of the midbrain reticular formation. RSA was also inhibited by 5-HT1A related anxiolytics such as buspirone, gepirone, and ipsapirone. The effects of 8-OH-DPAT and SM-3997 on the hippocampal RSA were blocked by pindolol, which has 5-HT1A antagonistic activity. Direct microinjection of these 5-HT1A selective agonists into the hippocampus inhibited generation of the hippocampal RSA. These findings indicated that 8-OH-DPAT and SM-3997 inhibited the hippocampal RSA by acting on hippocampal 5-HT1A receptors.

GABAergic agents on the medial septal nucleus affect hippocampal theta rhythm and acetylcholine utilization

Neurons of the medial septal nucleus are important in regulating the physiological activity of the hippocampus. If intraseptal injection of putative neurotransmitter substances affects the turnover rate of hippocampal acetylcholine, then concomitant changes would be expected in the electrophysiologic activity of the hippocampus. A GABA agonist, muscimol, was injected into the medial septum of rats and the effects on hippocampal electrical activity and acetylcholine utilization were studied. The intraseptally injected muscimol (100 ng) resulted in hippocampal electrographic records containing low amplitude asynchronous waves and significantly less rhythmic slow activity (RSA, 6–9 Hz), compared to control injections of saline. This effect was antagonized by prior intraseptal injection of bicuculline (3 μg). The hippocampal electrical activity returned to normal within 100 min. The utilization of acetylcholine was significantly reduced by intraseptal muscimol at times after administration when electrographic activity was also altered, and spontaneous behavioral movement was increased. These results suggest a physiological connection between hippocampal RSA generation and GABAergic mechanisms in the septum.

Identical responses of the two hippocampal theta generators to physiological and pharmacological activation

The possible existence of two separate RSA generators in the dorsal hippocampus raises questions as to the degree of coupling or independence of both. In order to answer these questions bipolar EEG recording were made in the CA1 and dentate gyrus of freely moving rats during conditions of RSA generation by different manipulations. The quantitative EEG parameters of simultaneous records were compared and cross correlation functions were calculated. Results indicate that even under different conditions of inducing RSA (physiological activation or injection of arecoline and nicotine) yielding RSA with different frequency characteristics, the quantitative EEG parameters were similar in both recordings. In addition, a high degree of concordance of both EEG was evidenced in the cross correlation function. These observations are discussed in terms of a high degree of coupling between both RS generators.