A natural history of Nevis and the rest of the English Leeward Charibee Islands in America : with many other observations on nature and art, particularly an introduction to the art of decyphering /

Goldsmiths'-Kress no. 08164.

Steganometrographia, sive Artificium novum & inauditum : quo quilibet etiam Latinae linguae & poëseos ignarus soliusque maternae linguae beneficio instructus epistolam Latino aut Germanico idiomate & quidem elegiaco carmine scribere potest & secretos animi sui conceptus absenti manifestare absque omni latentis secreti suspicione : cum Geomantia metrica utrumque artificium spatio horae dimidiae addisci potest /

Colophon: Ulmae : Typis Vogelii.

Geheimschreibkunst in Versen : dadurch ein jeder, der auch die lateinische Sprache und Dichtkunst nicht versteht, allein durch Hülfe seiner Muttersprache einen lateinischen oder deutschen Brief, und zwar in einem elegiaschen Gedichte schreiben und einem Abwesenden die geheimen Gedanken seines Herzens ohne allen Verdacht eines darunter verborgenen Geheimnisses offenbaren kann : welches Kunststück in Zeit von einer halben Stunde ein jedes zu erlernen fähig ist : nebst einer neuen Punctirkunst in Versen /

Signatures: a-c⁸ d⁶.

Résumé de La cryptographie dévoilée; ou L'art de traduire ou déchiffrer toutes les écritures en quelques caractères et en quelques langues que ce soit, qouique l'on ne connaisse ni ces caractères ni ces langues; appliqué aux langues française, allemande, anglaise, latine, et italienne; suive d'un précis analytique des langues écrites, au moyen duquel on peut les traduire, sans en avoir aucune connnaissance préalable.

J. S. Galland, Bibl. of cryptology,

Product cipher negotiation with on-line evaluation for private communication over computer networks

A method is proposed to offer privacy in computer communications, using symmetric product block ciphers. The security protocol involved a cipher negotiation stage, in which two communicating parties select privately a cipher from a public cipher space. The cipher negotiation process includes an on-line cipher evaluation stage, in which the cryptographic strength of the proposed cipher is estimated. The cryptographic strength of the ciphers is measured by confusion and diffusion. A method is proposed to describe quantitatively these two properties. For the calculation of confusion and diffusion a number of parameters are defined, such as the confusion and diffusion matrices and the marginal diffusion. These parameters involve computationally intensive calculations that are performed off-line, before any communication takes place. Once they are calculated, they are used to obtain estimation equations, which are used for on-line, fast evaluation of the confusion and diffusion of the negotiated cipher. A technique proposed in this thesis describes how to calculate the parameters and how to use the results for fast estimation of confusion and diffusion for any cipher instance within the defined cipher space.

On Graph-Based Cryptography and Symbolic Computations

We have been investigating the cryptographical properties of in nite families of simple graphs of large girth with the special colouring of vertices during the last 10 years. Such families can be used for the development of cryptographical algorithms (on symmetric or public key modes) and turbocodes in error correction theory. Only few families of simple graphs of large unbounded girth and arbitrarily large degree are known. The paper is devoted to the more general theory of directed graphs of large girth and their cryptographical applications. It contains new explicit algebraic constructions of in finite families of such graphs. We show that they can be used for the implementation of secure and very fast symmetric encryption algorithms. The symbolic computations technique allow us to create a public key mode for the encryption scheme based on algebraic graphs.

Probabilistic Models in Cryptography, Coding Theory and Tests for PRNG

2000 Mathematics Subject Classification: 94A29, 94B70

Plaintext Recovery in DES-like Cryptosystems Based on S-boxes with Embedded Parity Check

We describe an approach for recovering the plaintext in block ciphers having a design structure similar to the Data Encryption Standard but with improperly constructed S-boxes. The experiments with a backtracking search algorithm performing this kind of attack against modified DES/Triple-DES in ECB mode show that the unknown plaintext can be recovered with a small amount of uncertainty and this algorithm is highly efficient both in time and memory costs for plaintext sources with relatively low entropy. Our investigations demonstrate once again that modifications resulting to S-boxes which still satisfy some design criteria may lead to very weak ciphers. ACM Computing Classification System (1998): E.3, I.2.7, I.2.8.

Quantum computing and post-quantum cryptography

One of the main practical implications of quantum mechanical theory is quantum computing, and therefore the quantum computer. Quantum computing (for example, with Shor’s algorithm) challenges the computational hardness assumptions, such as the factoring problem and the discrete logarithm problem, that anchor the safety of cryptosystems. So the scientific community is studying how to defend cryptography; there are two defense strategies: the quantum cryptography (which involves the use of quantum cryptographic algorithms on quantum computers) and the post-quantum cryptography (based on classical cryptographic algorithms, but resistant to quantum computers). For example, National Institute of Standards and Technology (NIST) is collecting and standardizing the post-quantum ciphers, as it established DES and AES as symmetric cipher standards, in the past. In this thesis an introduction on quantum mechanics was given, in order to be able to talk about quantum computing and to analyze Shor’s algorithm. The differences between quantum and post-quantum cryptography were then analyzed. Subsequently the focus was given to the mathematical problems assumed to be resistant to quantum computers. To conclude, post-quantum digital signature cryptographic algorithms selected by NIST were studied and compared in order to apply them in today’s life.