Ruhr-Universität Bochum (RUB): Open Journal Systems
Not a member yet
4280 research outputs found
Sort by
Tilmann Heil: Comparing Conviviality. Living with Difference in Casamance and Catalonia. Cham: Palgrave Macmillan, 2020
Get PDFLehrveranstaltungen katalanischer Thematik an den Hochschulen des deutschen Sprachbereichs im Sommersemester 2024 und im Wintersemester 2024/2025
Get PDF
Nostalgia Cipher: Can Filtered LFSRs Be Secure Again? An Application to Hybrid Homomorphic Encryption with Sub-50 ms Latency
No full textLinear Feedback Shift Registers (LFSRs) combined with non linear filtering functions have long been a fundamental design for stream ciphers, offering a wellunderstood structure that remains easy to analyze. However, the introduction of algebraic attacks in 2003 shifted the focus toward more complex designs, as filtered LFSRs required larger registers to maintain security. While this was seen as a drawback at the time, it is no longer a limiting factor, and emerging cryptographic applications benefit from specialized designs—challenges that filtered LFSRs can effectively address. In this work, we propose a new filtered LFSR design, called Nostalgia, tailored for Hybrid Homomorphic Encryption (HHE). We use a weightwise quadratic function as filtering function, leveraging its efficiency in the HHE setting while ensuring security against classical attacks. We also discuss the parameter selection of our design and demonstrate its efficiency in this setting by providing a proof-of-concept implementation. In terms of latency, our HHE solution outperforms current state-of-the-art for TFHE-based HHE (Baudrin et al., Crypto 2025) by a factor of 6.1 times. By revisiting filtered LFSRs in light of modern security requirements, we aim to renew interest in their potential applications and stimulate further cryptanalysis efforts
What are the elements of experience?
No full textSeveral debates about conscious experience make reference to its parts, aspects, components, or, as we might neutrally say, elements. Are these elements themselves experiences? Are they unified with each other, and if so how? Are they more basic than, or less basic than, the whole field of consciousness? Or are there not really any distinct elements within experience at all? But it is not always clear what it means for experience to be divisible into many elements, and different conceptions of such elements may entail different, even opposing, answers to these debated questions. I argue that there are broadly two ways of thinking of the elements of experience: as constituent elements, the underlying parts that make something up, defined by their potential for independent existence, and as manifest elements, the distinguishable aspects that the subject can tell apart. I argue, moreover, that there is no obvious reason to assume that these two sorts of elements will line up with one another, and that this has important implications in multiple debates about the structure of conscious experience
David Gerlach /Mareen Lüke (Hrsg.): (Kritische) Fremdsprachenlehrkraft werden.
No full textRezension: Gerlach, David / Lüke, Mareen (Hrsg.): (Kritische) Fremdsprachenlehrkraft werden.Review: David Gerlach /Mareen Lüke (Hrsg.): (Kritische) Fremdsprachenlehrkraft werden
Stony Knowledge: Religious and Medical Encounters in Iranian Lapidaries
No full textThe use of precious stones for magical, apotropaic, and medical purposes has been well-documented since Antiquity. This article aims to demonstrate the complexity of the multi-religious material layered within the lapidaries of the Middle Iranian tradition, written in two Middle Iranian languages: Zoroastrian Middle Persian (Pahlavi Rivāyat accompanying the Dādēstān ī Dēnīg, chapter 64) and Sogdian (P.3). These two lapidaries, compiled in late Antiquity, contain different types of knowledge (medical, propitiatory, protective, etc.), some of which are shared by both lapidaries. Meanwhile, others, in the case of the Sogdian one, represent a specific cultural-religious development in Central Asia
History Carved on a Tombstone: Did the Descendants of the Poet Yazīd b. Miqsam al-Thaqafī Continue until the Twelfth Century?
No full textThis paper aims to edit and analyse an unpublished Arabic tombstone from the Ibn ʿAbbās public cemetery in Ṭāʾif. It also explores a related historical theme, i.e., the continuity of the descendants of an Arab poet down to the twelfth century. This tombstone contains the name of a deceased individual, linked to Yazīd b. Miqsam al-Thaqafī, an influential poet from Ṭāʾif in the eighth century AD (second century AH). This connection necessitates an examination of the poet Yazīd b. Miqsam al-Thaqafī\u27s family to establish connections between the deceased and Yazīd, as well as the relationship between Yazīd and the Umayyad caliphs
Improved Differential Cryptanalysis of SPEEDY
No full textSPEEDY is a family of lightweight block ciphers designed by Leander et al. Several differential attacks have been reported on the SPEEDY variants. However, nearly all of these attacks are based on differential characteristics with probabilities that differ from their reported values. These discrepancies arise from incorrect calculations of the (key-averaged) probability, particularly in consecutive steps within one round without intermediate key addition. In this paper, we revisit all reported differential characteristics and accurately calculate their key-averaged probabilities using quasidifferential trails. We extend this to also estimate the fixed-key probability. Our analysis reveals several characteristics with zero or significantly altered probability, invalidating several proposed attacks. We further implement a search algorithm and find a 5.5-round differential distinguisher that can be used to mount a full-round key-recovery attack with a data complexity of 2183 and a time complexity of 2185. The memory complexity varies: in the chosen-plaintext setting, it is 2156, whereas in the chosen-ciphertext setting, it is 236
Generalizations of ChiChi: Families of Low-Latency Permutations in Any Even Dimension
No full textAt Eurocrypt’25, Belkheyar et al. introduced a new non-linear layer called ChiChi or χχ. ChiChi is built based on Daemen’s χ function, but crucially gives a permutation in even dimension divisible by four.In this work, we generalize their construction in multiple ways, prove their open conjecture regarding the algebraic degree of the inverse of ChiChi, and investigate the properties of it against key recovery attacks