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1

Stacyjne i mobilne źródło czasu i częstotliwości

Matuszewski Ł., Kubczak P., Jessa M.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2017

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nr 8-9

952--955, CD

PL

W artykule opisano właściwości oraz możliwości wykorzystania źródła sygnału taktowania i synchronizacji STFS oraz mobilnego źródła sygnału referencyjnego SYN-Rb, opracowanych na Wydziale Elektroniki i Telekomunikacji Politechniki Poznańskiej. Sygnały wyjściowe źródeł spełniają wymagania zalecenia ITU-T G.703.9. Źródła STFS i SYN-Rb wykorzystują generator rubidowy i mogą być używane jako źródło sygnału wzorcowego klasy Stratum-1 dla synchronizacji dowolnego fragmentu sieci telekomunikacyjnej i teleinformatycznej, jako źródło sygnału wzorcowego w pomiarach parametrów sieci i urządzeń telekomunikacyjnych oraz do synchronizacji zestawów generatorów niższej klasy na potrzeby laboratoriów cywilnych oraz wojskowych.

EN

The article describes the features and possibilities of time and frequency source (STFS) and the mobile reference signal source (SYN-Rb). The devices were developed at the Faculty of Electronics and Telecommunications of Poznań University of Technology. The signals comply the requirements of ITU-T G.703.9. The STFS and SYN-Rb sources use rubidium oscillators and can be used as Stratum-1 class signal source for synchronization of any part of a telecommunications and data communications network, as a reference source for measuring, and for synchronization of lower class generators for civilian and military laboratories.

2

Measurement data acquisition system with mobile server

Matuszewski Ł., Woźniak W., Stołowski P., Jessa M.

Measurement Automation Monitoring

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2017

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Vol. 63, No. 5

174--176

EN

The paper describes an idea and the realization of a remote reading water meters system with wireless pictures transmission to the mobile server. The system consists of various water meters with installed electronic devices for measurement capturing. The measurements are read by taking a picture of the analog number indicators from the front panel. The pictures are send wirelessly to the mobile server which stores them until the acknowledgement from the main server is received. The mobile server is constructed of the microcomputer Raspberry Pi 3 connected with the XBee_PRO through adapter. The pictures transmission from the mobile server to the main server is realized by the Internet connection. The main server application allows recognizing the numbers from received pictures. The measurement data is available as digital numbers in a data base of the main server. The designed system is dedicated to the work in a low population density area.

3

PPS Quality Estimation From Different Receivers

Kubczak P., Matuszewski Ł.

Measurement Automation Monitoring

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2016

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Vol. 62, No. 11

383--386

EN

The article presents data analysis of the short-term and long-term-periodic characteristics of the PPS (Pulse Per Second) signal from the navigation systems. The signal arrival time to the Earth was assessed in relation to a high stability frequency source. The basic statistical properties of the signal were calculated, e.g. mean, variance, autocorrelation and actual distributions of random variables were depicted by using a histogram. The differences have been compared between the quality of the signal from the GPS network, the GLONASS network and their combination. The equipment offered by various manufacturers was assessed. Finally, the impact of the MAV filter (Moving Average) on the characteristics of the random variable was examined. At last, but not least, the autocorrelation was checked.

4

A proposal of output speed multiplication technique for true random number generators based on ring oscillators

Matuszewski Ł., Kubczak P.

Measurement Automation Monitoring

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2016

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Vol. 62, No. 5

157--159

EN

Nowadays modern cryptographic systems require a tremendous amount of keys. Very fast random number generators (RNGs) are needed to produce those keys in the requested time, but what to do when a solution that is already in use reaches the maximum speed? The aim of the paper is to find the answer to this question. In addition, generated random numbers should not leave a cryptographic system, because according to the Kerckhoffs thesis, the security of the whole system should be based only on a key. The cryptographic system should be enclosed within a single chip. In order to check new ideas and prove them, there were used NIST 800-22 test suite and restarts mechanism. The basic concept of the generator built of ring oscillators is still the same; ring oscillators are combined by XOR gates tree. A single ring oscillator consists of inverter, latch and NAND. This kind of construction provides a tool to make synchronous start and stop of all oscillators and the restart mechanism technique is applied in this manner. The speed of generation was increased by using multiple parallel generator trees to generate instantly the whole n-bit word. The paper shows that reproduction of the base structure is not a simple method of increasing the speed of generator. Moreover, it is always important to carefully consider all new ideas, because even if the NIST statistical test suite is passed, there is a chance that the restart mechanism will show some correlations that can be used during attack on the system.

5

Digital random bit generators implemented in FPGAs offered by various manufacturers

Kubczak P., Matuszewski Ł., Jessa M., Łoza S.

Measurement Automation Monitoring

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2015

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Vol. 61, No. 7

293--295

EN

In cryptography, we require that a random sequence should have excellent statistical properties as well as non-deterministic character. Combining multiple independent sources of randomness using the modulo two operation, significantly improves the statistical properties of the generated sequences and also affects the accumulation of true randomness generated in the oscillator sources. This is a very promising method of producing random sequences. In this paper, we compare the implementations of the RO-based combined random generator in various FPGAs technologies offered by various manufactures (Xilinx, Altera, Lattice). In this research, we used a NIST 800-22 statistical test suite to assess the statistical properties. The results show that the method of producing strings with a combined generator is the method stable in terms of technology. The results are similar for implementation in all FPGA used in the experiment. So, the proposed generator can be implemented in various programmable structures together with other components of a cryptographic system.

6

A wireless data acquisition and processing system

Matuszewski Ł., Woźniak W., Stołowski P., Jessa M.

Measurement Automation Monitoring

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2015

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Vol. 61, No. 7

330--332

EN

The paper describes an idea and realization of a system for collecting and processing data from different types of wireless distributed sensors. The system consists of wireless sensor networks. Each network consists of a server connected to the Internet and theoretically unlimited number of clients. The described server has been built with two types of microcomputers. It provides tools for data collecting and processing. A client, described in Section 5, can be implemented on any PC (Personal Computer) with Windows or Linux including the Raspberry PI and any other microcomputer with HDMI joint. It allows providing an interactive signboard. The data coming from a wireless measuring unit is stored in the server. Two versions of the measuring unit (Section 6) were developed. They differ in wireless modules (compared in Section 2). The first solution uses XBee-PRO 868. The second one uses CC-2530 working in ISM 2.4GHz band. The coverage comparison of both solutions is presented in Section 7. The system can be adjusted to measure any environmental value starting with temperature, humidity and ending with more advanced like the chemical composition of air. There is also included comparison with existing commercial solutions.

7

A random number generator using ring oscillators and the Keccak as post-processing

Łoza S., Matuszewski Ł., Jessa M., Kubczak P.

Measurement Automation Monitoring

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2015

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Vol. 61, No. 7

290--292

EN

In cryptography, sequences of numbers with unpredictable elements are often required. Such sequences should pass all known statistical tests for random sequences. Because sequences produced in real circuits are biased, they do not pass many statistical tests, e.g., the distribution of numbers is not uniform. Such random number sequences should be subjected to a transformation called post-processing. In this paper, a true random number generator is considered. It uses ring oscillators and the Keccak hash function as post-processing. This paper presents only simulation conditions for this approach since the post-processing part was done using x86 architecture on a PC.

8

A Random Number Generator Using Ring Oscillators and SHA-256 as Post-Processing

Łoza S., Matuszewski Ł., Jessa M.

International Journal of Electronics and Telecommunications

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2015

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Vol. 61, No. 2

199–204

EN

Today, cryptographic security depends primarily on having strong keys and keeping them secret. The keys should be produced by a reliable and robust to external manipulations generators of random numbers. To hamper different attacks, the generators should be implemented in the same chip as a cryptographic system using random numbers. It forces a designer to create a random number generator purely digitally. Unfortunately, the obtained sequences are biased and do not pass many statistical tests. Therefore an output of the random number generator has to be subjected to a transformation called postprocessing. In this paper the hash function SHA-256 as postprocessing of bits produced by a combined random bit generator using jitter observed in ring oscillators (ROs) is proposed. All components – the random number generator and the SHA-256, are implemented in a single Field Programmable Gate Array (FPGA). We expect that the proposed solution, implemented in the same FPGA together with a cryptographic system, is more attack-resistant owing to many sources of randomness with significantly different nominal frequencies.

9

Wykorzystanie funkcji skrótu do poprawy właściwości statystycznych ciągu liczb losowych

Matuszewski Ł., Łoza Sz., Jessa M.

Pomiary Automatyka Kontrola

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2014

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R. 60, nr 7

456--458

PL

W pracy przedstawiono sposób wykorzystania funkcji skrótu, na przykładzie funkcji SHA-256 (ang. Secure Hash Algorithm), do poprawy właściwości statystycznych ciągów liczb losowych. W badaniach wykorzystano pakiet testów statystycznych NIST 800-22 do oceny właściwości wytwarzanego ciągu metodę restartów i test chi kwadrat, dzięki którym możliwe jest wykazanie, czy dany generator produkuje ciąg z przeważającymi elementami deterministycznymi czy niedeterministycznymi. Proponowany układ może być z powodzeniem zaimplementowany w każdym układzie FPGA (ang. Field Programmable Gate Array).

EN

Random sequences play a key role in many contemporary cryptographic systems. To increase the efficiency and robustness to attacks, it is recommended to integrate a source of random numbers with a cryptographic system using these numbers. Unfortunately, the list of non-deterministic physical phenomena available in digital circuits is rather short and practically includes jitter and metastable states. It is expected that the generator produces sequences that pass all known statistical tests and that the sequences are unpredictable and attack resistant. A generator that satisfies these expectations is named a true random number generator (TRNG). This paper presents a novel method for producing random bits with the use of jitter observed in ring oscillators. The method uses a Galois ring oscillator introduced recently and the hash function. To assess the quality of output sequences, the statistical test suite prepared by National Institute of Standards and Technology (NIST) and the restart mechanism were used. The proposed system can be implemented in any Field Programmable Gate Array (FPGA).

10

Generator ciągów losowych wykorzystujący stany metastabilne zaimplementowany w układzie FPGA firmy Xilinx

Kubczak P., Jessa M., Matuszewski Ł.

Pomiary Automatyka Kontrola

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2014

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R. 60, nr 7

450--452

PL

W wysokiej klasy systemach bezpieczeństwa informacji klucze kryptograficzne nie powinny być generowane na zewnątrz systemu, a klucze prywatne, w przeciwieństwie do publicznych, nigdy nie powinny opuścić systemu. Jeśli system bezpieczeństwa jest realizowany w jednym układzie scalonym, klucze powinny być generowane w tym samym układzie. Realizacja generatorów liczb losowych w cyfrowych układach reprogramowalnych jest więc istotnym zagadnieniem. W artykule przedstawiono nową metodę wytwarzania ciągów losowych, opartą o zjawisko metastabilności występujące w układach cyfrowych oraz uwagi na temat sensowności wykorzystania tego fizycznego efektu występującego we współczesnych, powszechnie dostępnych układach cyfrowych.

EN

The security of cryptographic systems relates mainly to the protection of confidential keys. In high-end information security systems, cryptographic keys should never be generated outside the system and private keys should never leave the system. For the same reason, if the security system is implemented in a single chip (cryptographic system on chip), the keys should be generated inside the same chip. Implementation of random number generators in logic devices, including configurable logic devices, is therefore an important issue. In this paper, we present a new method of generating random digits based on a physical phenomenon occurring in digital circuits. Thus, the proposed generator can be implemented in different Field Programmable Gate Arrays (FPGAs) with other elements of the cryptographic system. If the underlying physical process cannot be controlled, the generator output is unpredictable and/or uncontrollable. The statistical characteristics of TRNGs are closely related to the quality of the entropy source, but also to the randomness extraction method. The statistical quality of the generator was verified with the use of NIST statistical test suite. A discussion of the utility of metastable states for producing random numbers with metastable states in commercially available FPGAs is also presented.

11

A digital true random number generator implemented in different Xilinx FPGAs

Matuszewski Ł., Jessa M.

Pomiary Automatyka Kontrola

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2013

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R. 59, nr 8

742--744

EN

In cryptography we often require sequences of numbers with unpredictable elements. Such sequences cannot be produced by purely deterministic systems. A novel method for producing true randomness and increasing the randomness of a combined TRNG using ring oscillators is described. In this paper we show that the proposed method provides similar results for generators implemented using different technologies offered by Xilinx. Thus, the proposed generator can be implemented in different FPGAs with other elements of a cryptographic system.

PL

W kryptografii często wymaga się ciągów liczb złożonych z nieprzewidywalnych elementów. Takie sekwencje nie mogą być wytwarzane w systemach czysto deterministycznych. Inżynierowie muszą opracować źródła losowości, których właściwości muszą być ocenione i potwierdzone przez niezależne badania, przynajmniej doświadczalnie. W artykule pokazano, że proponowana metoda wytwarzania losowości jest stabilna pod względem technologicznym. Uzyskano bardzo zbliżone rezultaty dla generatorów losowych zrealizowanych w strukturach FPGA (Field Programmable Gate Array) wykonanych w różnych technologiach jakie oferuje firma Xilinx. W żadnym przypadku nie korzystano z manualnego rozmieszczania elementów w matrycy FPGA, aby uzyskać lepsze rezultaty. Położenie poszczególnych składników zależało tylko od oprogramowania dostarczanego przez producenta. Zatem proponowany generator może być implementowany w różnych układach FPGA razem z innymi elementami systemu kryptograficznego.

12

Producing Random Bits with Delay-Line-Based Ring Oscillators

Jessa M., Matuszewski Ł.

International Journal of Electronics and Telecommunications

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2013

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Vol. 59, No. 1

41-50

EN

One of the sources of randomness for a random bit generator (RBG) is jitter present in rectangular signals produced by ring oscillators (ROs). This paper presents a novel approach for the design of delays used in these oscillators. We suggest using delay elements made on carry4 primitives instead of series of inverters or latches considered in the literature. It enables the construction of many high frequency ring oscillators with different nominal frequencies in the same field programmable gate array (FPGA). To assess the unpredictability of bits produced by RO-based RBG, the restarts mechanism, proposed in earlier papers, was used. The output sequences pass all NIST 800-22 statistical tests for smaller number of ring oscillators than the constructions described in the literature. Due to the number of ROs with different nominal frequencies and the method of construction of carry4 primitives, it is expected that the proposed RBG is more robust to cryptographic attacks than RBGs using inverters or latches as delay element.

13

Wykorzystanie zasobów FPGA do wyrównywania faz przebiegów taktujących

Matuszewski Ł., Jessa M., Ślęzak P.

Pomiary Automatyka Kontrola

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2012

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R. 58, nr 7

623-625

PL

W artykule opisano projekt układu do wyrównywania fazy przebiegu o powielonej częstotliwości do fazy przebiegu, którego częstotliwość powielono. Zaproponowany algorytm wyrównywania faz można zaimplementować w układzie FPGA, w którym producent przewidział mechanizm powielania częstotliwości sygnału wejściowego. Algorytm jest bardzo oszczędny w wykorzystaniu zasobów i nie wymaga konstruowania detektorów fazy o dużej rozdzielczości pomiaru różnicy faz.

EN

The paper describes design of a circuit that aligns the phase of a signal with multiplied frequency to the phase of a signal whose frequency is multiplying. The proposed phase aligning algorithm can be implemented in an Field Programmable Gate Array (FPGA) which supports the mechanism of frequency multiplication. The algorithm is very economical in usage of the FPGA resources and it does not require to use phase error measurements with high resolution. The principle of its work is illustrated in Figs. 1 and 2. A circuit that implements the algorithm consists of a START/STOP detector, a delay T whose value must be greater than the period of the signal with multiplied frequency, two latches and a delay line built into the FPGA whose value is controlled by a simple control module. Instead of measuring the value of the phase error between START and STOP signals, we check if signal START gets ahead of signal STOP or if it is delayed. If Qa="1" and Qb="0", the delay of the delay line from input START is increased by a quant. If Qa="1" and Qb="1" the delay of this line is decreased by a quant. In other cases the control circuit does not perform any operation. Subsequent checks are performed with frequency of signal STOP. In the design described in this paper the IODELAY line, available in Virtex-5 (XC5VLX50T), is used. The elementary delay of this line is about 75 ps. The phase alignment error observed for multiplication coefficients from 2 to 32 is between 150 ps and 240 ps.

14

Ocena histologiczna i radiologiczna kości królików po implantacji kompozytu CHAP-glukan

Borkowski L., Pawłowska M., Polkowska I., Karpiński M., Słowik T., Piersiak T., Matuszewski Ł., Ślósarczyk A., Ginalska G.

Engineering of Biomaterials

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2012

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Vol. 15, no. 114

28--33

PL

W eksperymencie in vivo zbadano podstawowe cechy dwufazowego kompozytu kościozastępczego tj. biozgodność i osteokonduktywność, a także jego właściwości osteoindukcyjne. Testowany kompozyt, przeznaczony do wypełniania ubytków kostnych, został wykonany z granul hydroksyapatytu węglanowego i polimeru polisacharydowego. Biomateriał został wszczepiony do kości piszczelowych królików na okres 1 lub 3 miesięcy. Po tym czasie zbadano stopień regeneracji kości na podstawie badań makroskopowych (radiologicznych) i mikroskopowych. Stwierdzono zaawansowane procesy osteointegracji i przebudowy kostnej w okolicy implantu, co wskazuje zarówno na osteokonduktywne, jak i osteoindukcyjne właściwości badanego biomateriału.

EN

Basic characteristics of a hydroxyapatite-glucan biomaterial such as biocompatibility, osteoconductivity and osteoinductive properties were tested in in vivo experiment. The two-phase composite, intended for filling bone defects, was made of carbonated hydroxyapatite granules and polysaccharide polymer. The biomaterial was implanted to the tibial metaphysis in rabbits for the 1- or 3-month period. Bone regeneration after that time was evaluated by radiology and histology. Our analysis showed advanced osseointegration and extensive bone remodelling in the direct vicinity of implants indicating osteoinductive and osteoconductive properties of the material studied.

15

Losowość generatora TRNG zaimplementowanego w FPGA

Jessa M., Matuszewski Ł., Jaworski M.

Pomiary Automatyka Kontrola

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2011

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R. 57, nr 8

880-882

PL

Random Number Generator) zbudowanego z wielu niezależnych generatorów pierścieniowych zaimplementowanych w tym samym układzie FPGA. Wykorzystując nową metodę odróżniania losowości od pseudolosowości wykazano, że zmniejszenie częstotliwości próbkowania wyjścia generatora pierścieniowego może zwiększyć losowość ciągu wytwarzanego przez generator TRNG. Otrzymany wynik oznacza, że generator może dostarczyć ciągów losowych użytecznych w kryptografii z większą szybkością od tej obserwowanej dla większej częstotliwości próbkującej.

EN

One of the simplest sources of purely digital true random bit sequences is the ring oscillator with output sampled by a signal coming from a low-frequency quartz oscillator. Combining XOR bit streams produced by many such generators (see Fig. 1) can significantly improve the statistical properties of the output sequence. As it is shown in the literature, this statement is true for deterministic and non-deterministic sources of random numbers. In cryptography, a user needs sequences with very good statistical properties but originating from a non-deterministic system. Therefore a method for distinguishing pseudo and true randomness for sequences produced by a combined true random number generator (TRNG) is necessary. In this paper the authors show that even a small amount of true randomness, present in a single ring oscillator, accumulates as a function of the number of ring oscillators used to produce the output stream. There is experimentally proved that in a real field programmable gate array (FPGA), the amount of randomness offered by the generator of Fig. 2 can be greater for smaller sampling frequency. Fig. 3 illustrates the behaviour of parameter mmin introduced in [6] as a function of the number K of source generators for four sampling frequencies fL: 100 MHz, 150 MHz, 200 MHz, and 250 MHz. The basic result of this paper is the statement that the efficient bit rate of streams useful for cryptography can be greater for smaller sampling frequencies than that observed for greater sampling frequencies.