...secret message undetectable to the unauthorized users. There is one more technique used to cipher the existence of the secret message which is cryptography. Cryptography scrambles a message so that it cannot be understood whereas steganography is a technique that is used to hide the secret message so that it is undetectable by the unintended users. Basically, the purpose of cryptography and steganography is to provide secret communication. Steganography can be used to cloak hidden messages in image, audio, video and even text files. The two most common methods used for hiding information inside a picture, audio and video files are LSB (Least Significant Bit) and Injection. In this paper, audio medium is used for steganography and a modified LSB algorithm is used to embed the secret...
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...be done in a secure method and routine without exposing any sort of private information to an unauthorized entity including cloud service providers. Trusted computing schemes, new cryptography techniques, and information centric security approaches [11ECC] can also be the other promising solutions to overcome several cloud computing security and privacy challenges. 2.8.2 Trusted Computing (TC) The Information Technology (IT) community, specifically the Trusted Computing Group (TCG), is attempting to build a set of technologies and mechanisms, e.g., data encryption, authentication, password management, identity and access management, network access control, and also disaster recovery, to provide assurance that cloud computing servers will fulfil the desired way of operation [28ECC]. The Trusted Computing Group (TCG) applies the trusted computing scheme to the Trusted Multi- Tenant Infrastructure (TMI) to create trust in an un-trusted environment, for example; public cloud computing service. This new concept purposes to enable clients to assess the trustworthiness of cloud service providers by applying a set of software and hardware technologies. The remote server attestation is among one of these technologies that actually allows customers to attest hosts [11ECC]. The Trusted Computing Group (TCG) starts building their solutions based on establishing a standard hardware module, the Trusted Platform Module (TPM), which basically carries out basic cryptography functions such as...
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...Symmetric Cryptography Secret writings have been found in many civilizations dating back to thousands of years where wide spread writings were adopted. Some of these civilizations included the Egyptians with their use of hieroglyphics, the Greeks and Spartan and the use of Scytale, and the Romans with the use of the Caesar Cipher. All these encryption methods could be thought of as symmetric encryption, which uses the same key to encrypt and decrypt the ciphertext. With a more contemporary look at symmetric key encryption with computer data, we can classify it into two categories called block ciphers and stream ciphers. The data in a block cipher would be broken down into specific sizes, for example 64-bit blocks or 128-bit blocks, which then the blocks would be encrypted separately. In stream ciphers, data would be encrypted in a stream of bits as oppose to dividing the data into blocks of bits. The decryption process for these two classification of symmetric encryption, of course, would be to use the same encryption key. Differences and Similarities with Symmetric and Asymmetric The fundamental difference between symmetric and asymmetric cryptography would be that asymmetric uses two keys, a public and private key, for encryption and decryption. If a private key is used to encrypt, then a related public key would be used to decrypt. This could also work the other way around when a public key is used to encrypt, then a related private key would be used to decrypt. Unlike...
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...[2] C. Blundo, A. De Santis, and D.R. Stinson. On the contrast in visual cryptography schemes. J. Cryptogr., 12:261-289, 1999. [3] J. B. Feng, H. C. Wu, C. S. Tsai, Y. F. Chang, and Y. P. Chu. Visual secret sharing for multiple secrets. Pattern Recognition, 41:3572-3581, 2008. [4] A. Ross and A. A. Othman, “Visual Cryptography for Biometric privacy”, IEEE Transaction on Information Forensics and Security, vol. 6, no. 1, Mar.2011. [5] M. Naor and B A. Shamir. Visual cryptography. in: A. De San tis (Ed.), Advances in Cryptology: Eurpocrypt'94, Lecture Notes in Computer Science, 950: 1-12, 1995. [6] C.C. Wu and L.H. Chen. A study on visual cryptography, Master Thesis. PhD thesis, Institute of Computer and Information Science, National Chiao Tung University, Taiwan, R.O.C., 1998. [7] M. Naor and A. Shamir “Visual cryptography:Improving the contrast via the cover base” IACR Eprint archive, 1996. [8] C. Blundo and A. De Santis and D.R. Stinson, “On the contrast in visual cryptography schemes”, Jurnal pf cryptography, vol. 12, pp. 261-289, 1996. [9] G. Ateniese and C. Blundo and A. De Santis and D.R. Stinson,“Extended Schemes for Visual Cryptography”, Theoretical Computer Science, 1996. [10] Z. Zhouand and G. R. Arce and G. Di Crescenzo, “Halftone visual cryptography” IEEE Trans. Image Process, vol. 15, no. 8, pp. 2441-2453, Aug. 2006. [11] C. Blundo and A. De Santis and M. Naor, “Visual cryptography for grey level image”, Information Processing Letters, vol. 75, pp. 255-259...
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...Cryptography & Pretty Good Privacy (PGP) 1. The need for cryptography in electronic communications Cryptography has been around for centuries; as long as there has been communication, there has been the need for privacy and safe, secure methods of transmission. Although many types of difficult problems can be classified as cryptography problems, what we are mostly concerned with today is the ability to keep transmissions private through the use of data encryption techniques. This has become an even greater issue due to the changing nature of communications since the information revolution. More and more people rely on electronic communications for the transmission of sensitive or personal data; e-mail, e-commerce, FTP, and HTML are all examples of technology that have already filtered into the social consciousness as primary ways for disseminating and gathering information and for exchanging goods and services. While this technological shift has made communication faster, easier, and better in many ways, it has also brought along with it a whole host of difficult problems and social policy issues. The main problem that comes with electronic communications is the ease with which transmissions can be eavesdropped or impersonated. Paper communications obviously have security problems as well: documents can be stolen, steamed open, have forged signatures or changed contents. However, if someone is trying to catch a specific transmission (or type of communication), it is much...
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...component and not interrupts the external and internal terms of resource. CRYPTOGRAPHY:- A) A cryptographer is one who practices or studies cryptography, a field primarily involved with keeping secret information secret. Mode cryptography is mostly concerned with encrypting digital information. B) A cryptography is the convert data text in cipher format. CIPHER:-- 1) A cipher (pronounced SAI-fur) is any method of encrypting text (concealing its readability and meaning). 2) It is also sometimes used to refer to the encrypted text message itself although here the term ciphertext is preferred 3) Cipher throw actual data are convert secure formatted and not to access an unauthorized user. 4) A block cipher is one that breaks a message up into chunks and combines a key with each chunk (for Example, 64-bits of text). A stream cipher is one that applies a key to each bit, one at a time. Most modern ciphers are block ciphers. TYPES OF CRYPTOGRAPH:- 1. SYMMATRIC 2. ASYMMATRIC SYMMATRIC KEY:- A symmetric key is the medium of two user b/w, it is a single, share key and private key type, symmetric key are used algorithem base and not access to an other user in symmatric key is sequencal manner transmittrd signal. [pic] Figure 1 - Symmetric Cryptography TYPES OF SYMMATRIC CRYPTOGRAPHY: --- 1. DES (DATA ENCRYPTION SECURITY) 2. AES (ADVANCE ENCRYPTION...
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...Tentative Syllabus CMSC 652 Cryptography and Data Security Instructor: Dr. Lomonaco 1. Classical cryptography 2. Abstract algebra: Groups, rings, fields 3. Linear feedback shift registers 4. Shannon theory, i.e., information theory 5. Block Ciphers and the AES 6. Cryptographic hash functions 7. The RSA crypto system 8. Public-key crypto and discrete logs 9. Signature Schemes 10. Pseudo-random number generators 11. Identification schemes and entity authentication 12. Key distribution 13. Key agreement schemes 14. Secret sharing schemes 15. Computational models and computational complexity 16. Zero-knowledge proof systems 17. Quantum cryptography Method of Evaluation: Homework: 25% ; Exam 1: 25% ; Exam 2: 25%; Final: 25%. All exams including the Final Exam will be with closed books, closed notes, and open mind. Late homework will not be accepted. Exams will be given only at the scheduled times. No makeup exams. Exceptions to this policy may be made in cases of extreme hardship. Academic Conduct: By enrolling in this course, each student assumes the responsibilities of an active participant in UMBC's scholarly community in which everyone's academic work and behavior are held to the highest standards of honesty. Cheating, fabrication, plagiarism, and helping others to commit these acts are all forms of academic dishonesty, and they are wrong. Academic misconduct could result in disciplinary action that may include, but is not limited to, suspension or dismissal. To read the full...
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...Hidden Markov Model | | Abstract While looking into cryptography and the building blocks that make up ciphers and theory, a mix of time and effort has produced concrete methods of cryptanalysis to identify the temporal pattern recognitions and algorithms necessary to decrypt cipher-text back to its plaintext root. This paper will look at the process of cribbing isomorphs to reveal the plaintext message, Gaussian Elimination and the process of back substitution, and the Hidden Markov Model to view visible output to that which was once hidden. Table of Contents Introduction 2 Cribbing Isomorphs 3 The Hidden Markov Model 4 Gaussian Elimination 5 Conclusion 6 Introduction In any cryptanalysts toolbox, there are a number of methods at their dispense which can aid in the deciphering of crypto-text messages back into their native plaintext message. Since the dawn of man, ways have been invented to hide secret information in an attempt to keep secret an intent, hide a plan, cover up a bad deed or whisper softly over distances. Encryption has proven the means to get this data over a medium and ensure that the integrity of the message arrives intact. Many times this information is intercepted and then the deciphering process begins. By knowing a certain amount about a message, cryptanalysts are able to piece the remaining message together by using cribbing, algorithms and back substitution methods to aid in revealing the unknown plaintext. This paper will examine...
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...“PALLADIUM CRYPTOGRAPHY” 1: ABSTRACT As we tend towards a more and more computer centric world, the concept of data security has attained a paramount importance. Though present day security systems offer a good level of protection, they are incapable of providing a “trust worthy” environment and are vulnerable to unexpected attacks. Palladium is a content protection concept that has spawned from the belief that the pc, as it currently stands, is not architecturally equipped to protect a user forms the pitfalls and challenges that an all-pervasive network such as the Internet poses. As a drastic change in pc hardware is not feasible largely due to economic reasons, palladium hopes to introduce a minimal change in this front. A paradigm shift is awaited in this scenario with the advent of usage of palladium, thus making content protection a shared concern of both software and hardware. In the course of this paper the revolutionary aspects of palladium are discussed in detail. 2: INTRODUCTION Cryptography is the method in which a message or file, called plain text, is taken and encrypted into cipher text in such a way that only authorized people know how to convert it back to plain text. This is done commonly in four ways: Secret key cryptography, public key cryptography, one way function cryptography and digital signatures. Unless the encryption technique used is very complex it is possible, with some effort, for crackers to decrypt files. Palladium is the code name...
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...ZETECH UNIVERSITY NAME: RUTERE JOAN WANJA REG. NO: DBIT-02-0035/2015 SCHOOL: I.T COURSE: DBIT UNIT NAME: OPERATING SYSTEMS TASK: CAT 2 LECTURER: MR FRED 1. Context Switching It is the process of storing of storing and restoring the state (context) of a process or thread so that the execution can be resumed from the same point at a later time. There are three potential triggers for a context switch: • Multitasking: Most commonly, within some scheduling scheme, one process needs to be switched out of the CPU so another process can run.This context switch can be triggered by the process making itself unrunnable, such as by waiting for an I/O or synchronization operation to complete. On a pre-emptive multitasking system, the scheduler may also switch out processes from being starved of CPU time, preemptive schedulers often configure a timer interrupt to fire when a process exceeds its time slice.This interrupt ensures that the scheduler will gain control to perform a context switch. • Interrupt Handling Modern architectures are interrupt driven.This means that if the CPU requests data from a disk, for example, it does not need to busy-wait until the read is over, it can issue the request and continue with some other execution. When the read is over, the CPU can be interrupted and presented with the read. For interrupts, a program called an interrupt handler that handles the interrupt from the disk. When an interrupt occurs...
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...Authentication? Authorization is the determination to if a user has the rights to perform specific tasks or actions on the network or system. Authorization is after Identification and Authorization where each verifies the user prior to verifying there role. 3. Provide at least 3 examples of Network Architecture Controls that help enforce data access policies at the LAN-to-WAN Domain level? 1. Smart Cards – A token CAC card that is used in tandem with a password 2. Passwords – User defined passwords that coincide with password standards. 3. Cognitive password – Pre-answered questions that hopefully only the user knows the answer to. 4. When a computer is physically connected to a network port, manual procedures and/or an automated method must exist to perform what type of security functions at the Network Port and Data Switch level for access control? Name and define at least three. Verify authorized access to the asset Verify the user is who they say they are through authentication Verify the configuration of the computer is compliant with local security standards.. 5. What is a Network Access Control (NAC) System? Explain its benefits in securing access control to a network. A NAC is the use of certain policy of the network information structure that temporarily limits access the certain recourses while authenticating the user. 6. Explain the purpose of a Public Key Infrastructure (PKI) and give an example of how you would implement it in a large organization...
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...Programme, Institute of Technology, Nirma University, Ahmadabad Email: 11MCA48@nirmauni.ac.in Abstract Cryptography is the study of Encryption techniques related to aspects of information security, such as confidentially or privacy, data integrity and entity authentication. Today’s world, for secure data transmission via Internet or any public network, there is no alternative to cryptography. The role of Cryptography is most important in the field of network security. The main goal of cryptography is Confidentiality, Integrity, Authentication, Non repudiation. Cryptography is widely used by governmental and intelligence agencies around the world to safe transmission of any format of messages online or offline. In cryptography, a substitution cipher is a method of encryption by which units of plaintext are replaced with cipher text, according to a regular system; the "units" may be single letters, pairs of letters, triplets of letters, mixtures of the above, and so forth. The receiver deciphers the text by performing an inverse substitution. Caesar cipher is an example of substitution cipher method. In this paper substitution cipher based cryptography algorithms are compared and performance is evaluated. Keywords Cryptography, substitution cipher, cryptanalysis, Caesar cipher, monoalphabetic cipher and Polyalphabetic cipher. Introduction A substitution cipher is a method of encryption by which units of plaintext are replaced with cipher text, according to a regular system;...
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...the 5980 octets of data field, we will slightly need more than 4 payloads. 5980/1480 = (4 x 1380) + 460 octets = 5520 octets + 460 octets = 5980 octets Be noted that the last 20 octets of data field will also go with a 20 octet’s header. Last payload = 460 octets (data field) + 20 octets (header) + padding = 480 octets + 920 octets (padding) = 1400 octets Finally, the IP fragments sequence will be as follow: Total Length = 1400More Flag = 1Offset = 0 | Total Length = 1400More Flag = 1Offset = 1380 | Total Length = 1400More Flag = 1Offset = 2760 | Total Length = 1400More Flag = 1Offset = 4140 | Total Length = 1400 More Flag = 0Offset = 5520 | b) Padding is a term used in cryptography. Normally, messages are to be encrypted in order to prevent the information in the message from leaking to other users. A number of random characters are added in the encryption either in the beginning or the end of the message to confuse the other users to know the exact length of the message when trying to break the encryption. Many classical ciphers arrange the plaintext into many patterns. For example squares, rectangle and so on. If the plaintext does not fit, random nonsense letters will be used to fit in the text and created a more complicated cryptanalysis...
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...History of Cryptography Developments in cryptography | Period | Development | 2000 BC | In Egypt, hieroglyphics were used in inscriptions. | 500-600 BC | Hebrews used the atbash method for encryption. In this method, each letter of the alphabet mapped to a different letter to hide the true meaning of a word. | 487 BC | The Spartans used the scytale for encryption – messages were written on paper wrapped around a wooden rod. The paper was then unwrapped and sent. The recipient could read the message only by wrapping this paper on a rod of the same length and diameter. | 100-44 BC | Julius Caesar used an encryption method similar to the atbash method. He shifted each letter of the alphabet by a fixed number of places to send encrypted messages. | 1379 | Gabrieli di Lavinde developed the nomenclator. | 1466-1467 | The first polyalphabetic cipher was invented, which was much stronger than the nomenclator. | 1518 | Johannes Trithemius invented a steganographic cipher in which each letter was represented as a word taken from a succession of columns. | 1553 | Giovan Batista Belaso introduced the use of a passphrase as the key for a repeated polyalphabetic cipher. In 1563, Giovanni Battista Porta introduced the digraphic cipher and classified ciphers as transposition, substitution, and symbol substitution. | 1585 | Blaise de Vigenere developed the polyalphabetic substitution cipher. William Frederick Friedman published a book on cryptography, and is known as the...
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...Cryptography Cryptography is an algorithm used for secure communication in the presence of third parties through encryption and decryption. It is a common method which enables users to store private or sensitive information transmits across an insecure network, like internet. In this case, it is suggested to use for protecting and guarding the UPS official website information transaction of the between UPS and its customers. In encryption process, the original or ordinary information (Plaintext) is converted into an unintelligible text (Ciphertext) that only the authorized parties with the key are able to read. The authorized parties perform decryption by reversing the process of encryption which converts the Ciphertext back into Plaintext with the key that given by the originator. As both UPS and its customers can take part in being information sender or receiver, the public key and private key holder can be interchanged. Symmetric Cryptography is suggested for the ease of implementation as symmetric-key cryptography makes encryption which both the sender and receiver share the same key. Besides, a message authentication code (MAC) can be implied to provide integrity and authenticity assurances on the message. Integrity assurances detect accidental and intentional message changes, while authenticity assurances affirm the message's origin. Integrity assurances detect accidental and intentional message changes, while authenticity assurances affirm the message's...
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