Incorporation of Organic Growth Additives to Enhance In Vitro Tissue Culture for Producing Genetically Stable Plants

The growing demand for native planting material in ecological restoration and rehabilitation for agro-silvo-pastoral ecosystems has resulted in a major global industry in their sourcing, multiplication, and sale. Plant tissue culture is used for producing high-quality, disease-free, and true-to-type plants at a fast rate. Micropropagation can help to meet the increasing demand for planting material and afforestation programs. However, in vitro plant propagation is an expensive technique compared to conventional methods using suckers, seeds, and cuttings. Therefore, adopting measures to lower production costs without compromising plant quality is essential. This can be achieved by improving the culture media composition. Incorporating organic growth additives can stimulate tissue growth and increase the number of shoots, leaves, and roots in culture media. Organic growth supplementation speeds up the formation and development of cultures and yields vigorous plants. Plant regeneration from meristems (shoot tips and axillary buds) is a reliable way to produce true-to-type plants compared with callus and somatic embryogenesis regeneration, but in vitro culture environments can be mutagenic. Therefore, detecting somaclonal variations at an early stage of development is considered crucial in propagating plants. The genetic stability of in vitro regenerated plants needs to be ascertained by using DNA-based molecular markers. This review aims to provide up-to-date research progress on incorporating organic growth additives to enhance in vitro tissue culture protocols and to emphasize the importance of using PCR-based molecular markers such as RAPD, ISSR, SSR, and SCoT. The review was assessed based on the peer-reviewed works published in scientific databases including Science Direct, Scopus, Springer, JSTOR, onlinelibrary, and Google Scholar

Improving Additive and Multiplicative Homomorphic Encryption Schemes Based on Worst-Case Hardness Assumptions}

In CRYPTO 2010, Aguilar et al. proposed a somewhat homomorphic encryption scheme, i.e. an encryption scheme allowing to compute a limited amount of sums and products over encrypted data, with a security reduction from LWE over general lattices. General lattices (as opposed to ideal lattices) do not have an inherent multiplicative structure but, using a tensorial product, Aguilar et al. managed to obtain a scheme allowing to compute products with a polylogarithmic amount of operands. In this paper we present an alternative construction allowing to compute products with polynomially-many operands while preserving the security reductions of the initial scheme. Unfortunately, despite this improvement our construction seems to be incompatible with Gentry\u27s seminal transformation allowing to obtain fully-homomorphic encryption schemes. Recently, Brakerski et al. used the tensorial product approach introduced by Aguilar et al. in a new alternative way which allows to radically improve the performance of the obtained scheme. Based on this approach, and using two nice optimizations, their scheme is able to evaluate products with exponentially-many operands and can be transformed into an efficient fully-homomorphic encryption scheme while being based on general lattice problems. However, even if these results outperform the construction presented here, we believe the modifications we suggest for Aguilar et al.\u27s schemes are of independent interest

Enabling PERK on Resource-Constrained Devices

PERK is a digital signature scheme submitted to the recent NIST Post-Quantum Cryptography Standardization Process for Additional Digital Signature Schemes. For NIST security level I, PERK features sizes ranging from 6kB to 8.5kB, encompassing both the signature and public key, depending on the parameter set. Given its inherent characteristics, PERK\u27s signing and verification algorithms involve the computation of numerous large objects, resulting in substantial stack-memory consumption ranging from 300kB to 1.5MB for NIST security level I and from 1.1MB to 5.7MB for NIST security level V. In this paper, we present a memory-versus-performance trade-off strategy that significantly reduces PERK\u27s memory consumption to a maximum of approximately 82kB for any security level, enabling PERK to be executed on resource-constrained devices. Additionally, we explore various optimizations tailored to the Cortex M4 and introduce the first implementation of PERK designed for this platform

A Practicable Timing Attack Against HQC and its Countermeasure

In this paper, we present a practicable chosen ciphertext timing attack retrieving the secret key of HQC. The attack exploits a correlation between the weight of the error to be decoded and the running time of the decoding algorithm of BCH codes. For the 128-bit security parameters of HQC, the attack runs in less than a minute on a desktop computer using 5441 decoding requests and has a success probability of approximately 93 percent. To prevent this attack, we propose a constant time algorithm for the decoding of BCH codes. Our implementation of the countermeasure achieves a constant time execution of the decoding process without a significant performance penalty

BIKE: Bit Flipping Key Encapsulation

Submission to the NIST post quantum standardization proces

Signature et identification pour l'anonymat basées sur les réseaux

Lattice-based cryptography has known during the last decade rapid develop- ments thanks to stronger security properties. In fact, there exist lattice-based cryp- tographic systems whose security is stronger than those based on the conventional number theory approach. The hard problems of lattices, for example the problem of finding short non-zero vectors, seems to resist quantum computers attacks. Mo- reover, the best existing algorithms solving them are exponential in time. The pur- pose of this thesis is the construction of public key cryptographic primitives for anonymity, whose security is based on the latter.In particular, we are interested in ring signature schemes. First, we propose a new formal definition of anonymity and we present a new ring signature scheme. Second, we give a rigorous study of security, following two definitions of unfor- geability. The first of which is unforgeability against chosen-subring attacks and the other one is unforgeability with respect to insider corruption.Afterwards, we present a new ring identification scheme and we develop a full analysis of its security. Finally, we show that the techniques used to build this scheme, can be used to construct a threshold ring identification scheme.La cryptographie basée sur les réseaux a connu depuis quelques années un très fort développement notamment du fait qu’il existe des systèmes cryptographiques basés sur les réseaux avec des propriétés de sécurité plus fortes que dans les cas plus classiques de théorie des nombres. Les problèmes difficiles des réseaux, par exemple le problème de trouver des vecteurs courts non nuls, semblent résister aux attaques utilisant des ordinateurs quantiques et les meilleurs algorithmes qui existent pour les résoudre sont exponentiels en fonction du temps. L’objet de cette thèse est la construction de primitives cryptographiques à clé publique pour l’ano- nymat dont la sécurité repose sur des problèmes difficiles des réseaux.Nous nous intéressons aux schémas de signature de cercle. Tout d’abord, nous proposons une nouvelle définition d’anonymat et nous exposons un nouveau schéma de signature de cercle. Ensuite, nous donnons une étude de sécurité rigoureuse suivant deux définitions de résistance la contrefaçon. La première est la résistance à la contrefaçon contre les attaques à sous-cercles choisis et la deuxième est la résistance à la contrefaçon contre les attaques de corruption interne.Nous présentons ensuite un nouveau schéma d’identification de cercle et nous développons une analyse complète de sa sécurité. Enfin, nous montrons que les techniques utilisées pour construire le schéma précédent peuvent être utilisées pour construire un schéma d’identification de cercle à seuil

Lattice-based signature and identification schemes for anonymity

La cryptographie basée sur les réseaux a connu depuis quelques années un très fort développement notamment du fait qu’il existe des systèmes cryptographiques basés sur les réseaux avec des propriétés de sécurité plus fortes que dans les cas plus classiques de théorie des nombres. Les problèmes difficiles des réseaux, par exemple le problème de trouver des vecteurs courts non nuls, semblent résister aux attaques utilisant des ordinateurs quantiques et les meilleurs algorithmes qui existent pour les résoudre sont exponentiels en fonction du temps. L’objet de cette thèse est la construction de primitives cryptographiques à clé publique pour l’ano- nymat dont la sécurité repose sur des problèmes difficiles des réseaux.Nous nous intéressons aux schémas de signature de cercle. Tout d’abord, nous proposons une nouvelle définition d’anonymat et nous exposons un nouveau schéma de signature de cercle. Ensuite, nous donnons une étude de sécurité rigoureuse suivant deux définitions de résistance la contrefaçon. La première est la résistance à la contrefaçon contre les attaques à sous-cercles choisis et la deuxième est la résistance à la contrefaçon contre les attaques de corruption interne.Nous présentons ensuite un nouveau schéma d’identification de cercle et nous développons une analyse complète de sa sécurité. Enfin, nous montrons que les techniques utilisées pour construire le schéma précédent peuvent être utilisées pour construire un schéma d’identification de cercle à seuil.Lattice-based cryptography has known during the last decade rapid develop- ments thanks to stronger security properties. In fact, there exist lattice-based cryp- tographic systems whose security is stronger than those based on the conventional number theory approach. The hard problems of lattices, for example the problem of finding short non-zero vectors, seems to resist quantum computers attacks. Mo- reover, the best existing algorithms solving them are exponential in time. The pur- pose of this thesis is the construction of public key cryptographic primitives for anonymity, whose security is based on the latter.In particular, we are interested in ring signature schemes. First, we propose a new formal definition of anonymity and we present a new ring signature scheme. Second, we give a rigorous study of security, following two definitions of unfor- geability. The first of which is unforgeability against chosen-subring attacks and the other one is unforgeability with respect to insider corruption.Afterwards, we present a new ring identification scheme and we develop a full analysis of its security. Finally, we show that the techniques used to build this scheme, can be used to construct a threshold ring identification scheme

Improved Lattice-Based Threshold Ring Signature Scheme

ISBN : 978-3-642-38615-2International audienceWe present in this paper an improvement of the lattice-based threshold ring signature proposed by Cayrel, Lindner, Rückert and Silva (CLRS) [LATINCRYPT '10]. We generalize the same identification scheme CLRS to obtain a more efficient threshold ring signature. The security of our scheme relies on standard lattice problems. The improvement is a significant reduction of the size of the signature. Our result is a t-out-of-N threshold ring signature which can be seen as t different ring signatures instead of N for the other schemes. We describe the ring signature induced by the particular case of only one signer. To the best of our knowledge, the resulted signatures are the most efficient lattice-based ring signature and threshold signature

Adapting Lyubashevsky's signature schemes to the ring signature setting

Basing signature schemes on strong lattice problems has been a long standing open issue. Today, two families of lattice-based signature schemes are known: the ones based on the hash-and-sign construction of Gentry et al.; and Lyubashevsky’s schemes, which are based on the Fiat-Shamir framework. In this paper we show for the first time how to adapt the schemes of Lyubashevsky to the ring signature setting. In particular we transform the scheme of ASIACRYPT 2009 into a ring signature scheme that provides strong properties of security under the random oracle model. Anonymity is ensured in the sense that signatures of different users are within negligible statistical distance even under full key exposure. In fact, the scheme satisfies a notion which is stronger than the classical full key exposure setting as even if the keypair of the signing user is adversarially chosen, the statistical distance between signatures of different users remains negligible. Considering unforgeability, the best lattice-based ring signature schemes provide either unforgeability against arbitrary chosen subring attacks or insider corruption in log-sized rings. In this paper we present two variants of our scheme. In the basic one, unforgeability is ensured in those two settings. Increasing signature and key sizes by a factor k (typically 80 − 100), we provide a variant in which unforgeability is ensured against insider corruption attacks for arbitrary rings. The technique used is pretty general and can be adapted to other existing schemes

Wavelet Transform Associated with the q-Dunkl Operator

[[abstract]]In this paper, we present some new elements of harmonic analysis re- lated to the q-Dunkl operator introduced in [1], we dene and study the q-wavelets and the continuous q-wavelet transforms associated with this operator. Next, as an application, we give inversion formulas for the q-Dunkl intertwining operator and its dual using q-wavelets