Tartu Ülikooli
digitaalarhiiv ADA
ADA, Tartu Ülikooli digitaalarhiivi sisuks on peamiselt Tartu Ülikooli monograafiad, doktoritööd, üliõpilastööd, lõputööd, magistritööd, õppematerjalid, Tartu Ülikooli raamatukogus digiteeritud materjalid ning Tartu Ülikooli teadlaste isikuarhiivid. Digitaalarhiivis olevaid materjale hoitakse turvaliselt ja varustatakse püsilingiga. Teenuse haldamise ja arendamisega tegeleb Tartu Ülikooli raamatukogu.
Valdkonnad ADAs
Valige valdkond, et selle kogusid sirvida.
Doktoritööd al. 2004. MSc, PhD (ETD)
E-õppe materjalid
Tartu Ülikooli raamatukogu
Tartu Ülikooli muuseum
Humanitaarteadused ja kunstid
Loodus- ja täppisteadused
Meditsiiniteadused
Sotsiaalteadused
Eesti Muusika- ja Teatriakadeemia
Eesti Teadusagentuur ja teised asutused
Haridus- ja Teadusministeerium
Tartu Ülikooli kirjastus
Hiljutised sisestused
Solving Anagrams with Integer Linear Programming
(Tartu University Library, 2025) Zajac, Pavol; Selep, Tomáš; Antal, Eugen; Antal, Eugen; Marák, Pavol
"Given some sequence of letters, an anagram is formed by changing their order to create a different text. In a historical context, anagrams were popular mainly as puzzles, but they are also connected to classical transposition ciphers. To solve an anagram means to rearrange the letter sequence to a form that is acceptable as a word or sentence in some language.
In this article, we formalize the anagram solving problem. We focus on anagrams based on a simplified language model based on fixed dictionaries. We study the applicability of known methods for this problem. We propose a method of anagram solving based on integer linear programming. The new method is not strictly superior to existing methods but provides new tools to tackle the problem. The new representation shows potential for integration with Word2Vec representation of words for finding potentially meaningful anagrams in natural languages."
A Florentine ‘polyalphabetic’ cipher in the 15th century
(Tartu University Library, 2025) Vito, Marco; Antal, Eugen; Marák, Pavol
The 15th century in Italy was a period of revolution in cryptography. Leon Battista Alberti developed the first western polyalphabetic cipher, while the monoalphabetic system spread throughout the peninsula. The aim of this study is to present a never before published late medieval 15th-century Florentine polyalphabetic cipher, explain its functioning, and shed light on a system—specifically the polyalphabetic cipher—that, although seemingly unused during the 15th century, was in fact employed in Florentine diplomacy.
Solving a 750-Letter General Bigram Substitution Challenge
(Tartu University Library, 2025) Schmeh, Klaus; Dunin, Elonka; Van Eycke, Jarl; Helm, Louie; Antal, Eugen; Marák, Pavol
The general bigram substitution cipher is an encryption method originating in the Renaissance. It operates using a substitution table that maps each possible letter pair (bigram) to a unique replacement. While conceptually straightforward, this cipher is notably challenging to break, particularly when dealing with short ciphertexts. To inspire further research, one of the authors initiated a bigram substitution challenge featuring a 750-character ciphertext. In this paper, we present the solution to that challenge, achieved by two other authors using a hill climbing algorithm combined with a scoring function based on 8-gram (eight-letter sequence) frequencies. Since no prior 8-gram frequency statistics existed for the English language, one of the authors developed a comprehensive dataset by analyzing 2 terabytes of text, including 5.8 million books and the entire content of Wikipedia. This achievement, to our knowledge, marks the shortest bigram substitution ciphertext ever successfully decrypted. Furthermore, we propose a new challenge based on a 600-character ciphertext and invite readers to tackle it, setting the stage for future advancements in this field.
A Caribbean Directory-based Encryption during the American War of Independence
(Tartu University Library, 2025) Pierrot, Cécile; Chaline, Olivier; Damoiseau-Malraux, Gaspard; Mekhail, Paul; Perret, Ludovic; Antal, Eugen; Marák, Pavol
The corpus of letters we are studying is located at the Archives Nationales d'Outre-Mer in Aix-en-Provence, France. These late 18th-century letters come from Saint Domingue (now Haiti), a French colony in the Caribbean Sea of which Bellecombe, the author, was governor. They were written in the context of the American War of Independence, in which France took part on the side of the Americans. We have reconstructed Bellecombe's correspondence with the Secretary of State for the Navy, in Versailles: the archives contain hundreds of letters in clear and three encrypted letters, including some clear/cipher pages that were our lever for reconstructing part of the key, and 96 % of the encrypted letter that was opaque at first. From a cryptanalytical point of view, Bellecombe used a directory-based encryption. The common use of this type of cipher in the 17th and 18th-century European countries raises the question of the method to be used (then as now!) to decode such messages.
DECODE2LOD: Connecting the DECODE Database with the Linked Open Data Cloud
(Tartu University Library, 2025) Palma, Cosimo; Megyesi, Beáta; Antal, Eugen; Marák, Pavol
This paper presents a novel approach to enhancing the analytical power and interoperability of historical cryptology data by transforming the DECODE database into a Linked Open Data (LOD) resource. We introduce a methodology for modeling encrypted historical documents and cipher keys as a knowledge graph, encompassing ontology development, data transformation, and SPARQL-based querying. This integration enables complex queries across domains, encourages collaboration beyond cryptology, and aligns DECODE with broader efforts in digital humanities and open science. By bridging historical cryptology with LOD principles, we offer a scalable framework for enriching specialized research databases through semantic technologies.
A new attack on the mysterious inscription of Santa Maria La Nova
(Tartu University Library, 2025) Palma, Cosimo; Bonavoglia, Paolo; Rugova, Yll; Antal, Eugen; Marák, Pavol
Expanding upon the established hypothesis of monoalphabetic substitution with potential transposition and polyalphabetic elements, this analysis of the Santa Maria la Nova epigraph incorporates Ancient Greek, Old Church Slavonic, Old Romanian and Old Albanian, thus exploring the possibility that the cipher’s plaintext derives from historically under-examined languages, particularly those with cultural and historical ties to medieval Naples and its Eastern Mediterranean networks. Special attention is given to aligning the analyzed corpora with the epigraph's actual textual rendering and to the evaluation of multilingualism.
Decipherment of Historical Manuscripts with Unknown or Rare Writings: The DESCRYPT Project
(Tartu University Library, 2025) Megyesi, Beáta; Fornés, Alicia; Héder, Mihály; Heil, Raphaela; Kopal, Nils; Láng, Benedek; Rattenborg, Rune; Waldispühl, Michelle; Antal, Eugen; Marák, Pavol
We present a newly funded research program, DESCRYPT, aimed at deciphering and analyzing historical texts with rare or unknown scripts. The project leverages advancements in computational linguistics, artificial intelligence (AI), and image processing, alongside traditional philological methods, to develop innovative tools for transcription, recognition, and interpretation of historical writings with rare/unknown scripts, including ciphertexts. By integrating interdisciplinary expertise, DESCRYPT addresses the challenges posed by complex and undeciphered texts, preserving and unlocking the secrets of our shared cultural heritage.
A Typology of Pseudo-Cryptology
(Tartu University Library, 2025) Láng, Benedek; Antal, Eugen; Marák, Pavol
Cipher and code systems can be classified in many ways, with numerous typologies available for organizing both modern and historical cryptographic systems based on their structure. In this article, I propose a different type of typology. I organize various ciphers and codes into a system based on the confirmability of their alleged or actual solutions. This approach places side by side ciphers (e.g., monoalphabetic and polyalphabetic) that would otherwise seem far apart in terms of encoding techniques, and it highlights methods (e.g., book ciphers) that typically do not play a central role in cryptology classifications. This typology becomes useful when attempting to navigate the flood of sensational new cipher-breaking claims that surface weekly in popular media, helping to form a preliminary opinion on whether a proposed solution is arbitrary and unfounded or well-grounded and deserving of professional trust.
Antonio Elio “Cipher” and his Polyphonic-Syllabic Cipher
(Tartu University Library, 2025) Lasry, George; Biermann, Norbert; Simonetta, Marcello; Antal, Eugen; Marák, Pavol
Antonio Elio (Helius) (1506–1576) was a Roman Catholic prelate who served as Bishop of Capodistria and Pola and Titular Patriarch of Jerusalem. Also a prolific cryptographer in the service of Pope Paul III, he is credited for the invention of polyphonic ciphers. In this article, we provide an overview of his career and work in cryptography and describe an ingenious polyphonic-syllabic cipher he designed. Although several matching plaintext-ciphertext segments were available, reconstructing the cipher key required a significant and unusual amount of time, underscoring the cipher’s high level of security. Ciphertext-only cryptanalysis for such a cipher would be extremely difficult and nearly impossible, even with modern computing, without prior knowledge of the principles of its complex design.
Overview of Ciphers Used by the Czechoslovak "Maffie"
(Tartu University Library, 2025) Krajčovič, Jozef; Antal, Eugen; Antal, Eugen; Marák, Pavol
This paper provides an overview of encryption systems and steganographic techniques used by the Czechoslovak Maffie, which was an anti-Austrian underground resistance organization in 1914-1918.