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В этой статье я сначала объясню некоторые принципы квантовой механики, затем перейду к обсуждению основ квантовых криптографических протоколов BB84, B92 и протоколов на основе ЭПР, и, наконец, я завершу статью несколькими комментариями о стратегиях отслеживания. и практическое применение квантовой криптографии.Я рассмотрю некоторые технологические вопросы, которые необходимо решить перед внедрением.

This study analyses the characteristics and possibilities of protection of privacy rights on the Internet portals in the Republic of Serbia. The article examines the relationship between these rights and the right to freedom of expression. In accordance with that, the article presented the self-regulatory documents of the Republic of Serbia concerning the media, that serve as the ethical standard of journalists' conduct: The Journalist's Code of Ethics from 2006 and the Guidelines for the Application of the Journalist's Code of Ethics in Online Environment from 2016, the honoring of which is under the jurisdiction of the Press Council. The research is based on the analysis of cases where the privacy rights, dignity and integrity of persons were violated and it includes comparative research of the media reporting on two portals (Espreso and B92) during two separate periods of monitoring the compliance with the the Journalist's Code and the Guidelines in Online Environment. The first monitoring was conducted in cooperation with the Press Council in the period from October 1st to November 30th 2017, while the repeated independent monitoring was conducted in the period from March 1st to March 31 2018, in order to determine whether there had been an improvement on both portals. The monitoring showed that there are violations of privacy rights on both portals, most often in the 'Chronicle' section. The privacy of the victims is violated more frequently than that of the suspects. Also, despite there being a clear reference in the Code about the need of protecting the identity of minors, there have been multiple violations of children's right to privacy, especially in the 'Chronicle' section.

We propose a decoy-pulse protocol for frequency-coded implementation of B92 quantum key distribution protocol. A direct extension of decoy-pulse method to frequency-coding scheme results in security loss as an eavesdropper can distinguish between signal and decoy pulses by measuring the carrier photon number without affecting other statistics. We overcome this problem by optimizing the ratio of carrier photon number of decoy-to-signal pulse to be as close to unity as possible. In our method the switching between signal and decoy pulses is achieved by changing the amplitude of RF signal as opposed to modulating the intensity of optical signal thus reducing system cost. We find an improvement by a factor of 100 approximately in the key generation rate using decoy-state protocol. We also study the effect of source fluctuation on key rate. Our simulation results show a key generation rate of 1.5×10-4/pulse for link lengths up to 70km. Finally, we discuss the optimum value of average photon number of signal pulse for a given key rate while also optimizing the carrier ratio., {"references":["W. Y. Hwang, \"Quantum key distribution with high loss: Toward global\nsecure communication,\" Phys. Rev. Lett., vol. 91, no. 057901, 2003.","J. M. Merolla et al., \"Phase-modulation transmission system for quantum\ncryptography,\" Opt. Lett., vol. 24, 1999.","P. Kumar and A. Prabhakar, \"Bit error rates in a frequency coded quantum\nkey distribution system,\" Optics Communications, vol. 282, no. 18, pp.\n3827-3833, 2009.","X. Ma et al., \"Practical decoy state for quantum key distribution,\"\nPhysical Review A, vol. 72, no. 012326, 2005.","Y. Zhao et al., \"Simulation and implementation of decoy state quantum\nkey distribution over 60 km telecom fiber,\" in Proceedings of IEEE\nInternational Symposium on Information Theory, 2006, pp. 2094-2098.","D. Gottesman et al., \"Security of quantum key distribution with imperfect\ndevices,\" Quantum Information and Computation, vol. 4, p. 325, 2004.","G. Brassard and L. Salvail, \"Advances in cryptology eurocrypt-93,\"\nLecture Notes in Computer Science, vol. 765, pp. 410-423, 1994.","J.-Z. Hu and X.-B. Wang, \"Reexamination of the decoy-state quantum key\ndistribution with an unstable source,\" Phys. Rev. A, vol. 82, p. 012331,\n2010."]}

Çalışmanın 1. Bölümde kriptoloji terimleri ve kriptolojinin tarihçesi verilmiş, çeşitli simetrik ve asimetrik şifreleme sistemleri tanıtılmış, bu sistemler içinde doğru uygulandığında kırılamayacağı 1949 yılında bir AT&T mühendisi olan Shannon tarafından teorik olarak da ispatlanmış olan Vernam Şifresi detaylı olarak incelenmiştir. Vernam şifreleme sisteminin sağladığı mutlak güvenlik tamamen rastgele seçilmiş tek kullanımlık anahtarın gizliliğine ve dağıtımının güvenliğine bağlıdır. Fakat prensip olarak, herhangi bir klasik özel kanal kullanıcılara izlenildiklerini fark ettirmeden pasif olarak takip edilebilir ve gizli kalması gereken anahtarın bir rakibin eline geçmesine fırsat verebilir. Bu noktada kuantum kriptografi anahtar dağıtım probleminin çözüldüğü, anahtarın güvenliğinin fizik kuralları ile korunduğu bir anahtar dağıtım tekniği olarak karşımıza çıkmaktadır. Klasik şifreleme sistemlerinin güvenlikleri bazı zor matematiksel problemlerin hesaplanabilme zorluğuna dayanırken, bu teknik kuantum mekaniğine dayanır. Kuantum mekaniğinin ilkelerine göre hatasız iletim hatlarında kaynaktan hedefe iletilmekte olan verinin bozulması arada istenmeyen biri tarafından verinin okunmaya çalışıldığı anlamına gelir. Bu avantajdan yararlanmak suretiyle kullanıcılar arasında eşit anahtar dizilerinin yüzde yüz güvenli biçimde paylaşılabilmesi için BB84, B92, SARG, Ekert protokolü gibi çeşitli anahtar dağıtım protokolleri öne sürülmüştür. Bu protokollerin prensiplerine 2. Bölümde yer verilmiştir.Çalışmanın diğer bölümlerinde genel olarak 1989 yılında başarıyla gerçekleştirilen ilk kuantum anahtar dağıtımı denemesinden günümüze kadar yapılan ve bu alandaki gelişmelere öncülük eden çalışmalara göz atılmış, KAD sistemlerinde yer alan ışık kaynakları, dedektörler ve kuantum kanallar ile kanal kusurlarından kaynaklanan hataların düzeltilmesi ve anahtarın gizliliğinin artırımı için destekleyici işlemler hakkında bilgi verilmiş, 9. Bölümde kuantum kriptografinin güvenliğine değinilmiş, 10. ve son Bölümde ise kuantum kriptografinin geleceği, beklentiler ve ülkemiz açısından önemi tartışılmıştır.Anahtar Kelimeler: Kuantum Kriptografi, Kuantum Anahtar Dağıtım Protokolleri, BB84, B92, SARG, Dolanıklık, Bell Eşitsizlikleri, Gizlilik Artırımı, Yan Kanallar. In the first part of this study cryptological terms and history of cryptology have been provided, various symmetrical and asymmetrical cryptographic systems have been defined and in these systems Vernam cipher theoretically proven by AT&T engineer Shannon that the system cannot be hacked if practiced properly has been examined in details. Absolute security provided by Vernam cryptographic system completely depends on randomly selected single use of the key?s confidentiality and the security of its distribution. But principally any of the classic private channels can passively be eavesdropped without its notice and may give the opportunity to change hands for the key which should be kept confidential. Here the quantum cryptography appears us as a key distribution technique where the problem is solved and the security of the key has been protected by physical rules. Although the securities of the classical cryptographic systems are based on the complication of the calculation of some mathematical problems, this technique depends on quantum mechanics. Principles of quantum mechanics assert that the corruption of the data transferred to the target from accurate transmission lines imply that the data has been tried to be read by an eavesdropper. In order to share equal key indexes hundred percent safely among the users by benefiting from this advantage, various key distribution protocols set forth such as BB84, B92, SARG, Ekert. The principals of those protocols are allowed in the 2nd part of the study.In the other parts of the study, in general, the studies following the achievement reached first in 1989 regarding key distribution experiment until today and the studies leading to the developments in this field have been looked through and information regarding light sources in QKD systems, detectors and quantum channels with the supporting procedures for correction of the errors originating from channel defects and privacy amplification have been provided, referred to quantum cryptography security in part 9 and the future of quantum cryptography, expectations and its importance regarding our country have been negotiated in tenth and the last part.Key Words: Quantum Cryptography, Quantum Key Distribution Protocols, BB84, B92, SARG, Entanglement, Bell Inequalities, Privacy Amplification, Side Channels. 108