Le monnayage d'argent de Poseidonia : une étude historique de coins

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Applied batch cryptography

The material presented in this thesis may be viewed as comprising two key parts, the first part concerns batch cryptography specifically, whilst the second deals with how this form of cryptography may be applied to security related applications such as electronic cash for improving efficiency of the protocols. The objective of batch cryptography is to devise more efficient primitive cryptographic protocols. In general, these primitives make use of some property such as homomorphism to perform a computationally expensive operation on a collective input set. The idea is to amortise an expensive operation, such as modular exponentiation, over the input. Most of the research work in this field has concentrated on its employment as a batch verifier of digital signatures. It is shown that several new attacks may be launched against these published schemes as some weaknesses are exposed. Another common use of batch cryptography is the simultaneous generation of digital signatures. There is significantly less previous work on this area, and the present schemes have some limited use in practical applications. Several new batch signatures schemes are introduced that improve upon the existing techniques and some practical uses are illustrated. Electronic cash is a technology that demands complex protocols in order to furnish several security properties. These typically include anonymity, traceability of a double spender, and off-line payment features. Presently, the most efficient schemes make use of coin divisibility to withdraw one large financial amount that may be progressively spent with one or more merchants. Several new cash schemes are introduced here that make use of batch cryptography for improving the withdrawal, payment, and deposit of electronic coins. The devised schemes apply both to the batch signature and verification techniques introduced, demonstrating improved performance over the contemporary divisible based structures. The solutions also provide an alternative paradigm for the construction of electronic cash systems. Whilst electronic cash is used as the vehicle for demonstrating the relevance of batch cryptography to security related applications, the applicability of the techniques introduced extends well beyond this.

Development of fourth-grade students’ understanding of experimental and theoretical probability

Students explored variation and expectation in a probability activity at the end of the first year of a 3-year longitudinal study across grades 4-6. The activity involved experiments in tossing coins both manually and with simulation using the graphing software, TinkerPlots. Initial responses indicated that the students were aware of uncertainty, although an understanding of chance concepts appeared limited. Predicting outcomes of 10 tosses reflected an intuitive notion of equiprobability, with little awareness of variation. Understanding the relationship between experimental and theoretical probability did not emerge until multiple outcomes and representations were generated with the software.

New Perspectives on the Roman Coinage on the Eastern Limes in the Late Republican and Roman Imperial Period

The Ph.D. thesis discusses the monetary development in Roman Syria and Judaea in the Late Republican and the Early Imperial Period, from a numismatic, archaeological and historical point of view. In effect, the work focuses on the 1st century B.C. to the 1st century A.D., that is, the assumed time of introduction of Roman denarii to the region. The work benefits from the silver coin hoards of Khirbet Qumran recently published by the author. Though discovered as early as 1955 at Qumran, where the famous Dead Sea Scrolls had been found prior to that in 1947, most hoards remained unpublished until 2007. A second important source utilized is the so-called Tax Law from Palmyra in Syria. Its significance lies in the fact that Palmyra used to be one of the most important cities on the Silk Road, along which luxury goods were transported into the Roman Empire and Rome itself. During the research conducted, studies of the provincial coinage of Judaea (A.D. 6-66) shed new light on the authority of the Roman governors in economic and monetary matters in eastern Mediterranean regions. Furthermore, a new suggestion as to the length of the mandate period of Pontius Pilate is made. The extent of Emperor Augustus monetary reforms as well as the military history of Judaea are discussed in the light of new analytical studies, which show that the production of Roman base metal coins appears to have been a highly controlled process, contrary to popular opinion. Statistical calculations related to the coin alloy revealed striking similarities with Roman and other local metalwork found in Israel; a fact previously unknown. Results indicate that both Roman and local metalwork consisted of outstandingly systematized practises and may have exploited the same metal sources. Information: Kenneth Lönnqvist (*25.7.1962) has studied at the University of Helsinki since 1981. Furthermore, Lönnqvist has lived in the Mediterranean countries and the Near East, and made research there at various scientific institutions and universities for ca. 7 years. Contact and sales of thesis: kenneth.lonnqvist@helsinki.fi

Hanukkah lamp from Italy Coin

Obverse: 1 Lira silver coin. Reverse: Hanukkah lamp from Italy.

Port of Eilat Coin

Obverse: Silver 5 Lirot coin. Reverse: A stylized lighthouse, the seawall, stylized inscription.

Hanukkah lamp from North Africa Coin

Obverse: Silver 1 Lira coin. Reverse: Hanukkah lamp from North Africa

And He Gave up His Life in Battle Coin

Obverse: 1 Lira coin, torch and inscription. Reverse: Inside of a depressed pentagon there is a design of a war elephant bearing a turret and Greek soldiers equipped for battle. The elephant is being stabbed by Elazar.

Knesset Coin

Obverse: Silver 5 Lirot coin with large emblem of the State of Israel. Reverse: Design of the building of Knesset.

Theodore Herzl Centenary Coin

Obverse: silver 5 Lirot coin. Reverse: In the upper right portait of Theodore Herzl in rectangle with rounded corners. Below the emblem of the state of Israel.

Bar Mitzvah Coin

Obverse: Silver 5 Lirot coin, in the right side olive branch. Reverse: A stylized reproduction of an ancient Holy Ark which appears on a gold-vessel painted in the 13th century C.E.

Mikveh Israel Centenary Coin

Obverse: Silver 10 Lirot coin, a stylized spikelet of corn. Reverse: Schematic plough.

Half Shekel Coin

Obverse: Silver Half Lira coin. Reverse: A raised reproduction of an ancient silver half-shekel of beaded rim from the third year of the first Jewish revolt against the Romans 66-73 C.E.. At the center of the coin in a chalice inscription in the archaic Hebrew letters.

Half-Shekel Coin

Obverse: Silver Half Lira coin. Reverse: A raised reproduction of an ancient silver half-shekel of beaded rim from the third year of the first Jewish revolt against the Romans 66-73 C.E.. At the center of the coin in a chalice inscription in the archaic Hebrew letters.

Israel Museum Jerusalem Coin

Obverse: Silver 5 Lirot coin. Replica of the capital and part of a pillar, of the 7th century BCE found at Ramat Rachel on the outskirts of Jerusalem. Reverse: A stylized relief of the buildings of Israeli Museum in Jerusalem.