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Pseudorandom sequences are widely used in cryptography. Multiple recursive generators are an important class of pseudorandom sequence generators. A typical application is to obtain truncated sequences by truncating partial bits of the sequences output by the generators. This paper studies the predictability of truncated multiple recursive generators with unknown parameters. Given a few truncated digits of high-order bits output by a multiple recursive generator, we give a method based on lattice reduction to recover the parameters and the initial state of the generator. Our method is an extension of Stern’s algorithm which was proposed to predict the truncated sequences of linear congruential generators.

We discuss the distinctness problem of the reductions modulo MM of maximal length sequences modulo powers of an odd prime pp, where the integer MM has a prime factor different from pp. For any two different maximal length sequences generated by the same polynomial, we prove that their reductions modulo MM are distinct. In other words, the reduction modulo MM of a maximal length sequence is proved to contain all the information of the original sequence.

整数剩余类环上压缩导出序列简称环上导出序列, 是一类重要的非线性序列. 目前国际4G移动通信三大标准之一的ZUC算法所采用的序列源就是一类环上导出序列. 环上导出序列的非线性来源于压缩映射, 特别的, 如果该压缩映射是保熵的, 即压缩后序列和原始序列一一对应, 这时压缩后序列含有原始序列的所有信息, 这使得保熵压缩映射成为环上导出序列研究的核心问题. 本文基于序列的Garner分解提出了一种新的压缩方式, 即将整数剩余类环上本原序列压缩到其Garner分解下的最高权位序列, 并对部分情形给出了保熵性的证明. 本文结论可以给出范围更广的合数环上的压缩导出序列, 为环上导出序列在密码学中的进一步应用提供更多素材. 同时, 通过选取合适的参数, 根据本文结论可以得到拥有理想的周期特性、复杂的非线性结构以及易于软硬件实现的非线性序列.

同余发生器的可预测性问题, 即能否由一段截位序列还原发生器的参数和初态, 进而准确预测后面的序列, 是评估发生器安全性的重要研究课题. 本文研究在模数m = 2k 已知, 系数a, b未知的条件下, 二阶线性同余发生器xi+2 = axi+1 + bxi mod m 的可预测性问题. 我们给出一个基于格基约化算法的方法, 可以在已知一段连续的高位s 比特截位序列的条件下, 还原系数a, b 和初态x0, x1, 实现对序列的预测. 实验结果表明, 当模数m = 232, 发生器生成的序列为整数剩余类环Z/mZ 上的二阶本原序列时, 可以由140 拍连续的高位6 比特截位序列还原系数a,b 和初态x0, x1. 本文从逆向还原的角度探究二阶线性同余发生器的抗预测能力, 旨在为其在密码上的应用提供参考和指导.

整数剩余类环上线性递归序列(简称环上序列)是一类重要的伪随机序列, 在密码学中有广泛的应用. 截取环上序列的部分比特序列得到的截位序列是其常见的应用形式. 环上截位序列还原问题, 即由截位序列还原整体序列, 是环上序列安全性评估的重要研究课题. 设m是奇素数或不同奇素数之积, f(x)是Z/(m)上的n次本原多项式, 是由 f(x)生成的本原序列, 若已知序列的最低l比特序列, 序列元素个数为d, 如何还原整体序列？将问题转化为格上的最近向量的计算问题, 进一步证明：对于截位比特个数l大于等于2, 截位序列元素个数d大于等于在无穷范数的度量下, 如果能够计算d+n维格上的最近向量, 则可以以1-1/m的概率还原整体序列. 以ZUC密码标准的驱动序列进行实验, 由长度大约100拍的6比特截位序列, 可以还原出整体序列, 恢复未知的25比特序列. 根据5比特的截位序列, 若已知序列元素个数达到150左右, 能够成功还原的实验次数超过一半. 对截位比特个数l等于2的情形, 当本原多项式的次数小于4时, Z/(231-1)和 Z/(232-1)上的本原序列可以由最低2比特截位序列还原整体序列.

差分分析方法的核心是构造高效的差分区分器. 2019年Aron Gohr采用深度学习残差网络的方法构造差分区分器, 应用于减轮Speck32/64密码算法, 五轮和六轮的差分器成功率分别是0.929和0.788. 本文采用PU学习(positive-unlabeled learning)的方法, 对Speck32/64算法的差分对数据进行训练, 利用神经网络中的多层感知机与基于PU学习构造的损失函数, 训练得到了一个基于PU分类的差分区分器, 并对于减轮Speck32/64算法进行攻击, 五轮和六轮差分器成功率分别是0.965和0.860.

Red phosphor K2LiAlF6:Mn4+ has been synthesized by a cation-exchange method in HF solution. To optimize their optical properties, phosphors were synthesized using different reaction conditions. The K2LiAlF6:0.5%Mn4+ synthesized at 20°C for 4 h shows the highest luminescence intensity. The temperature-dependent emission intensity of the phosphor was investigated, and it was found to exhibit good thermal stability, making it a promising red phosphor candidate for warm WLEDs.

Mycoplasma bovis ( M. bovis ) is the causative agent of bovine mycoplasmosis, a disease that can lead to respiratory issues, otitis media, mastitis, and arthritis in cattle and causes huge economic losses to the cattle breeding industry. Although vaccination represents the most effective method for the prevention of M. bovis , there is a lack of commercially available subunit vaccines that are effective against this disease. Here, we developed several subunit vaccine candidates using different combinations of membrane proteins M27, M32, M498, and M663 derived from a M. bovis strain isolated in Guizhou Province, China. Subsequently, the immune efficacy of the subunit vaccine candidates was evaluated in mice through immunization and challenge experiments. The results showed that the M. bovis subunit vaccines constructed from different protein fusions (M27-32, M27-498, M27-663, M27-32–498, M27-32–663, M27-498–663, and M27-32–498-663) were capable of eliciting the secretion of specific antibodies in mice. Furthermore, these candidates also induced robust TNF-α, IFN-γ, IL-4, IL-5, and IL-6 in the serum of mice, suggesting the induction of Th1- and Th2-type immune responses. Microscopically, these M. bovis subunit vaccine candidates were also effective in reducing lung tissue damage caused by M. bovis infection, suggesting that they provide good protection against challenge with virulent M. bovis . Among the tested vaccine candidates, the M27-498–663 and the M27-32–498-663 subunit vaccine candidates demonstrated the most robust immune efficacy, laying the foundation for the effective control of M. bovis .

Objective： We aimed to perform a preliminary study of the association between induced pluripotent stem cell （iPS）-related genes and biological behavior of human colorectal cancer （CRC） cells, and the potential for developing anti-cancer drugs targeting these genes. Methods： We used real-time reverse transcriptase po- lymerase chain reaction （RT-PCR） to evaluate the transcript levels of iPS-related genes NANOG, OCT4, SOX2, C-MYC and KLF4 in CRC cell lines and cancer stem cells （CSCs）-enriched tumor spheres. NANOG was knockdowned in CRC cell line SW620 by lentiviral transduction. 3-（4,5-Dimethylthiazol-2-yl）-2,5- diphenyltetrazolium bromide （MTT） assays, plate colony formation, and a mouse xenograft model were used to evaluate alterations in biological behavior in NANOG-knockdown SW620 cells. Also, mock-knockdown and NANOG-knockdown cells were treated with 5-fluorouracil （5-FU） and survival rate was measured by MTT assay to evaluate drug sensitivity. Results： A significant difference in the transcript levels of iPS-related genes between tumor spheres and their parental bulky cells was observed. NANOG knockdown suppressed proliferation, colony formation, and in vivo tumorigenicity but increased the sensitivity to 5-FU of SW620 cells. 5-FU treatment greatly inhibited the expression of the major sternness-associated genes NANOG, OCT4, and SOX2. Conclusions： These results collectively suggest an overlap between iPS-related genes and CSCs in CRC. Quenching a certain gene NANOG may truncate the aggressiveness of CRC cells.

Ferroptosis and immune cell infiltration are important pathological events in spinal cord injury (SCI), but links between ferroptosis and immune microenvironment after SCI were rare reported. In our study, 77 FRDEGs were screened at 7 days after SCI. GO analysis of FRDEGs showed that aging (GO:0007568; P-value = 1.11E-05) was the most remarkable enriched for biological process, protein binding (GO:0005515; adjusted P-value = 4.44E-06) was the most significantly enriched for molecular function, cytosol (GO:0005829; adjusted P-value = 1.51E-04) was the most prominent enriched for cellular component. Meanwhile, Ferroptosis was significantly enriched both in KEGG (rno04216; adjusted P-value = 0.001) and GSEA (NES = 1.35; adjusted P-value = 0.004) analysis. Next, Hmox1 (Log 2 Fold change = 6.52; adjusted P-value = 0.004) was identified as one of hub genes in SCI-induced ferroptosis. In the results of immune cell infiltration analysis, proportion of microglia/macrophage was significantly increased after SCI, and Hmox1 was found to positively correlate to the M1 type microglia/macrophage abundance. Finally, effects of Hmox1 on ferroptosis and M1 type polarization were validated in vivo and in vitro. Summarily, we found that Hmox1 was the hub gene in SCI-induced ferroptosis and associated with the M1 type polarization.