17 research outputs found
Fault analysis and weak key-IV attack on Sprout
Armknecht and Mikhalev proposed a new stream cipher `Sprout\u27 based on the design specification of the stream cipher, Grain-128a. Sprout has shorter state size than Grain family with a round key function. The output of the round key function is XOR\u27ed with the feedback bit of the NFSR of the cipher. In this paper, we propose a new fault attack on Sprout by injecting a single bit fault after the key initialization phase at any arbitrary position of the NFSR of the cipher. By injecting a single bit fault, we recover the bits of the secret key of the cipher by observing the normal and faulty keystream bits at certain clockings of the cipher. By implementing the attack, we verify our result for one particular case. We also show that the Sprout generates same states for several rounds in key initialization phase for two different key-IV pairs, which proves that the key initialization round is having very poor period
Fault Analysis on the Stream Ciphers LILI-128 and Achterbahn
LILI-128 is a clock controlled stream cipher based on two LFSRs with one clock control function and one non-linear filter function. The clocking of the second LFSR is controlled by the first LFSR. In this paper we propose a fault algebraic attack on LILI-128 stream cipher. We first recover the state bits of the first LFSR by injecting a single bit fault in the first LFSR. After that we recover the second LFSR state bits by following algebraic cryptanalysis technique. We also propose fault attack on Achterbahn stream cipher, which is based on 8 NLFSRs, 8 LFSRs and one non-linear combining function. We first inject a single bit fault into the NLFSR-A then observe the normal and faulty keystream bits to recover almost all the state bits of the NLFSR-A after key initialization phase. One can apply our technique to other NLFSR-B, C, D to recover their state bits als
Some results on ACORN
In this paper we obtain a weakness in the design specification of ACORN, which is a competitor of CAESAR competition. We show that there exists a probabilistic linear relation between message bits and ciphertext bits, which holds with probability greater than . This is the first paper which finds a probabilistic linear relation between message and corresponding ciphertext bits of ACRON, and which holds with probability greater than . We also propose a new type of CPA attack on ACORN. By our attack method, it is possible to recover full initial state of the encryption phase of the cipher, and the attack has complexity . After obtaining the initial state of the encryption phase, one can invert the associated data loading phase and key-IV initialization phase to recover the secret key bits
Soil conservation issues in India
Despite years of study and substantial investment in remediation and prevention, soil erosion continues to be a major environmental problem with regard to land use in India and elsewhere around the world. Furthermore, changing climate and/or weather patterns are exacerbating the problem. Our objective was to review past and current soil conservation programmes in India to better understand how production-, environmental-, social-, economic- and policy-related issues have affected soil and water conservation and the incentives needed to address the most critical problems. We found that to achieve success in soil and water conservation policies, institutions and operations must be co-ordinated using a holistic approach. Watershed programmes have been shown to be one of the most effective strategies for bringing socio-economic change to different parts of India. Within both dryland and rainfed areas, watershed management has quietly revolutionized agriculture by aligning various sectors through technological soil and water conservation interventions and land-use diversification. Significant results associated with various watershed-scale soil and water conservation programmes and interventions that were effective for reducing land degradation and improving productivity in different parts of the country are discussed
Comparative efficacy of serratus anterior plane block (SAPB) and fentanyl for postoperative pain management and stress response in patients undergoing minimally invasive cardiac surgery (MICS)
Background: Fast-tracking plays a significant role in reducing perioperative morbidity and postoperative hospital stay by facilitating early extubation and optimal pain control. Attenuating the stress response to surgery also has a crucial function in enhancing recovery. Serratus anterior plane block (SAPB) is a recently described technique for chest wall analgesia. More data is required to find out the effectiveness of analgesia by SAPB for minimally invasive cardiac surgery (MICS).
Aim: The study aimed to assess the efficacy and safety of ultrasound-guided SAPB compared to fentanyl for controlling post-thoracotomy pain and stress response in patients undergoing MICS.
Setting and Design: Time framed comparative, prospective, and observational study.
Materials and Methods: Patients undergoing MICS for coronary artery bypass grafting under general anesthesia were randomly assigned into two groups. SAPB group (Group A) patients were given 0.2% of 20 ml ropivacaine followed by catheter insertion for continuous infiltration at the end of the procedure. Fentanyl group (Group B) patients were given fentanyl infusion for postoperative analgesia. The primary outcome measured changes in visual analog scale (VAS) score (pain) and cortisol levels (for stress response) in both groups.
Results: VAS score was significantly low in Group A when compared to Group B (P < 0.0001). Cortisol levels were also lower in the SAPB group. Hemodynamic parameters (systolic blood pressure, diastolic blood pressure, pulse rate, and oxygen saturation) were more stable in Group A with a lesser requirement of top-up analgesics.
Conclusion: SAPB was more effective than fentanyl in managing post-thoracotomy pain after MICS. Cortisol level was lower in the group that received SAPB
Genome-wide expression profile of steroid response in Saccharomyces cerevisiae
The response of the yeast Saccharomyces cerevisiae to human steroid hormone progesterone was studied by genomic expression profiling. The transcription profile data revealed that steroid response was a global phenomenon wherein a host of genes were affected. For example, 163 genes were upregulated and 40 genes were downregulated, by at least more than twofold. The major categories of upregulated genes included protein destination (15%), metabolism (14%), transport facilitation (12%), cell growth, cell division, and DNA synthesis (8%), and transcription (7%), while metabolism (22%), transcription (11%), intracellular transport (10%), cell growth, cell division, and DNA synthesis (10%), energy (8%), cell rescue, defense, and cell death (6%), and protein synthesis (6%) encoding genes were downregulated. Notwithstanding the fact that yeast cells do not possess commonly occurring steroid response cascade similar to higher eukaryotes, our results demonstrate that a short-term exposure to progesterone results in differential regulation of predominantly stress responsive genes
Responses of Pathogenic and Nonpathogenic Yeast Species to Steroids Reveal the Functioning and Evolution of Multidrug Resistance Transcriptional Networksâ–¿ â€
Steroids are known to induce pleiotropic drug resistance states in hemiascomycetes, with tremendous potential consequences for human fungal infections. Our analysis of gene expression in Saccharomyces cerevisiae and Candida albicans cells subjected to three different concentrations of progesterone revealed that their pleiotropic drug resistance (PDR) networks were strikingly sensitive to steroids. In S. cerevisiae, 20 of the Pdr1p/Pdr3p target genes, including PDR3 itself, were rapidly induced by progesterone, which mimics the effects of PDR1 gain-of-function alleles. This unique property allowed us to decipher the respective roles of Pdr1p and Pdr3p in PDR induction and to define functional modules among their target genes. Although the expression profiles of the major PDR transporters encoding genes ScPDR5 and CaCDR1 were similar, the S. cerevisiae global PDR response to progesterone was only partly conserved in C. albicans. In particular, the role of Tac1p, the main C. albicans PDR regulator, in the progesterone response was apparently restricted to five genes. These results suggest that the C. albicans and S. cerevisiae PDR networks, although sharing a conserved core regarding the regulation of membrane properties, have different structures and properties. Additionally, our data indicate that other as yet undiscovered regulators may second Tac1p in the C. albicans drug response
A genome-wide steroid response study of the major human fungal pathogen Candida albicans
In the absence of steroid receptors and any known mechanism of gene regulation by steroid hormones in Candida albicans, we did a genome-wide analysis of C. albicans cells treated with progesterone using Eurogentec cDNA microarrays to find the complete repertoire of steroid responsive genes. Northern blotting analysis was employed to validate the genes that were differentially regulated by progesterone in the microarray experiments. A total of 99 genes were found to be significantly regulated by progesterone, among them 60 were up-regulated and 39 were down-regulated. It was observed that progesterone considerably enhanced the expression of multi-drug resistance (MDR) genes belonging to ATP Binding Cassette (CDR1 and CDR2) super-family of multidrug transporters, suggesting a possible relationship between steroid stress and MDR genes. Several genes associated with hyphal induction and the establishment of pathogenesis were also found up-regulated. In silico search for various transcription factor (TF) binding sites in the promoter of the affected genes revealed that EFG1, CPH1, NRG1, TUP1, MIG1 and AP-1 regulated genes are responsive to progesterone. The stress responsive elements (STRE; AG4 or C4T) were also found in the promoters of several responsive genes. Our data sheds new light on the regulation of gene expression in C. albicans by human steroids, and its correlation with drug resistance, virulence, morphogenesis and general stress response. A comparison with drug induced stress response has also been discussed