Symmetric Vs Asymmetric Algorithms Computer Science Essay

Symmetric Vs A radial Algorithms Computer Science turn up info integrity, confidentiality and availability over the web, applications and storage means take up sprain the major(ip) concerns in ready reckoner world. If data ar exposed to an ack-ack guner, it get out have a signifi flush toilett impact to business. Cryptography has a major role to play to prevent attacks to sensitive data employing encoding and decoding mechanicss. There atomic number 18 two main blastes to encoding interchange competent and un regular, and apiece of them contains its own variety of encryption algorithmic rules. Both causas have their advantages and mischiefs as none of them excels at twain efficiency and high trade protection measures. As illustrated in this paper it is not sufficient enough to affair a single type of encryption systems in applications. Rapid development of network technology and expansion of entropy around the world, information security has to be balanced with process efficiency requiring interbreeding approaches. This paper discusses the advantages and disadvantages of severally type of steganography and proposes in reference to literature integration approaches.Index Terms -encryption, decryption, even algorithm, noninterchangeable algorithm, creation backbones, cipher text edition, PGP, GnuPG, hybrid encryption.IntroductionCryptography is the study of the mathematical techniques cerebrate to aspects of information security such as confidentiality, data integrity, mental object credentials, and entity trademark (Piper, 2002). Cryptography has many applications including those in notice management for digital converse ( colloquy equipment, electronic mail and data interchange, access prevail and audit trails, e-banking), commercialised software (software verification and virus detection).encryption of electronic contents has been considcred for Electronic Data Interchange (EDI), where contracts and purchase localize s are signed and delivered electronically. Similar system has been apply by the British banks for Electronic Funds Transfer (EFT) for Point Of gross sales (POS). For Local Area Networks (L.4Ns) the IEEE 802.10 LAN Security Working Group is currently drafting security standard employ public- pick up techniques for identify management.Access control to buildings or computers relies on social function of crys or Personal Identification morsel (PIN). Passwords are either stored to the computer or are dynamically generated utilize battery-powered devices (tokens). In round cases (e.g. in banking) the token is activated by entering a PIN. State-of-the art smart card devices embed private or payment data which flush toilet be decrypted as yen as the physical exerciser enters a password or provides biometric data (e.g. voice, fingerprint, handwritten signature, or s apprisened picture).In theory of cryptanalytics, the information to be encrypted is called the substance and t he exploit of disguising is known as encryption (or enciphering). The enciphered message is called the ciphertext or cryptogram. The algorithm use for this operation also has a second remark known as the enciphering strike. The process of obtaining the message from the ciphertext is known as decryption, and, in addition to the ciphertext, the deciphering algorithm needs a deciphering describe. The receiver will obtain the correct message, if they use the right deciphering key.An encryption system is said to be symmetric if, for distri exceptively corresponding pair of enciphering and deciphering keys, it is easy to determine the deciphering key from the enciphering key. If, on the another(prenominal)wise hand, it is computationally impossible to determine the deciphering key from the enciphering key, then we have a public key system or, else, an asymmetric system.Symmetric and asymmetric cryptanalysis are almost two different subjects, therefore the algorithms are differe nt, and the key management problems are different. In the sections below we present the main algorithms of each system and a comparison betwixt the algorithms of each system is performed. symmetric ALGORITHMSIn symmetric algorithms, the sender and receiver of messages and files share the like key for encryption and decryption. Symmetric algorithms have the advantage of not consuming too much computing power. The most typical examples are DES, trey-DES (3DES), liking, CAST5, BLOWFISH, TWOFISH.In symmetric algorithms an important aspect of their effectiveness is the strength of the key encryption or else the size of it of the key apply. Since the same key is utilise for encryption and decryption, the lasting the keys are, the harder to unlock them. Strong versus weak key is one of the typical classification of symmetric algorithms.DES (Data Encryption warning) was the first symmetric algorithm to be introduced by NIST (National Institute of Standards and Technology) in 1974 . DES uses one 64-bits key and many attacks have been recorded in literature against it and that caused the need to propose 3DES ( trinity DES). Triple DES (3DES) uses three 64-bits keys. Therefore, 3DES applies 3 times the core encryption method of DES however this makes it slower than other symmetric algorithms (Nadeem and Javed, 2005).In addition, NIST introduced AES (Advanced Encryption Standard) in 1997 as replacement of DES. AES uses various (128,192,256) bits keys. Yet Brute overstretch attack was the only effective unlocking mechanism against it trying all role combinations. Bruce Schneiers blowfish encryption method is even stronger with no effective attack to have been recorded since its release in 1993. Its effectiveness relies on using variable length key (32-448) and 128-bit is its default and a 64-bit block size although taking the risk of allowing the definition of weak keys (Nadeem and Javed, 2005).Running simulation tests, Nadeem and Javed (2005) showed that Blow fish has better transaction than other symmetric algorithms and no any security weak points to its record.AES and 3DES showed poor operation since it requires more processing power. Similar results have been produced in (Elminaam et al, 2009).ASSYMETRIC ALGORITHMSNowadays confidential messages around the world are encrypted and decrypted relying on asymmetric techniques. This is because the key used for encryption and decryption is not the same but rather it relies on a key distribution mechanism which is called public-private key distribution. Confidential messages are encrypted using the public key and rouse only be decrypted using the private key. RSA, DSA, ELGAMAL, TLS, PGP are some of the examples of asymmetric algorithms.RSA is one of the well known public key (asymmetric type of) algorithms used for generating digital signatures over messages (Das and Madhavan, 2009). In addition, NIST published the Digital Signature Standard (DSS) in 1991 for generating digital signatures . DSS uses the SHA-1 algorithm for calculating the message digest of the athletic field message and then applies the DSA (Digital Signature Algorithm) for creating the digital signature of the message base on the message digest. DSA is only used for performing digital signatures. It cannot be used for encryption and this is the main difference with RSA (Das and Madhavan, 2009).COMPARING SYMMETRIC AND ASSYMETRIC cryptology TECHNIQUESAdvantages and disadvantages of symmetric algorithms are illustrated in the turn off below (Panda and Kumar, 2011)AdvantagesDisadvantagesSimple method of encryptionAgree a priori a secret key sooner any message exchangeEncryption of personal user files and messages concur multiple keys one for each pair of message exchange or collaborationFaster than asymmetric techniquesSharing the secret key does not prove authenticity of sender or receiver of messagesRequires less computer resources attain management is a task requiring significant effortKey compro mise to a communication pair does not affect communication with other pairsKey exchange should also be a firm process requiring the implementation of its own repair channelCan use the same publicly known algorithm for encryptionstrength of security depends on size of keyAdvantages and disadvantages of symmetric algorithms are illustrated in the table below (Panda and Kumar, 2011)AdvantagesDisadvantagesMakes convenient the key distribution as only the public keys are sharedPublic key generation and distribution is postulate for activating the encryption mechanism requiring a verification process in its ownDigital signatures are generated through public key encryption hence verifying the authenticity of the senderIt is rather slow in comparison to symmetric algorithms and is not preferred for short messagesMessages accompanied by digital signature cannot be modified during transferIt requires a dope more processing powerDigitally signing a message is equivalent to a physical signa ture thus the recipient of the message cannot deny the authenticity of the senderLosing a private key can cause can cause widespread security compromise as all messages can be readHYBRID approachesThe main disadvantage of asymmetric algorithms is their slowness is comparison to the symmetric algorithms. One way to care this issue in many applications, is to apply a combination of both. A typical integration approach is the followinguse asymmetric keys for authenticationthen one or more symmetric keys can be generated and exchanged using the asymmetric encryption.Typical examples of this procedure are the RSA/ imagination combination of PGP2 or the DSA/BLOWFISH used by GnuPG.For instance, Mantoro and Zakariya (2010) proposed a unafraid(p) method of e-mail communication for android- ground mobile devices using a hybrid cryptosystem which combines AES 128 bit (symmetric) encryption, RSA 1024 bit (asymmetric) encryption and SHA-1 (hash) function. This approach had been tested with pla in text but not with email attachments or communication betwixt Android devices and other mobile platforms.PGP varietyOne of the main applications of public key encryption techniques is in the PGP (Pretty Good Privacy) program for data communication. It is primarily used for signing, encrypting emails, files, text and anything else that is involved in email communication (Zimmermann, 1995).RSA key of 1024 bits are still considered secure (given the available options of 512, 1024, 2048 bits). On the other hand, Kaliski (2003) considers that an 1024-bit RSA key can be broken in one year and that an 2048-bit RSA public key is secure enough for a PGP configuration which includes also the AES and the SHA-1 algorithm. RSA/IDEA/MD5 or any other other similar configuration is less secure according to Lenstra and Verheul (2003).PGP works as follows (Benz, 2001)compresses the plain message in order to reduce the pattern of the typical plaintextcreates a session key which is a random number, usually generated given mouse movements or keystrokesa symmetric encryption algorithm is applied on the random number (e.g. Triple DES, Twofish, CAST, or AES) to generate a one-time-only secret key (session key)additional input might be required by the user if the collected information is not sufficient enough (e.g. additional mouse movements, keystrokes)the session key is used along a symmetric algorithm to encrypt the message to a ciphertext.The session key is also encrypted using an asymmetric technique such as RSAThe recipient receives the ciphertext along with the public key-encrypted session key. and so the combination of the two encryption methods exploits the convenience of public-key encryption with the speed of symmetric encryption (Benz, 2001). Symmetric encryption is about 100 to 1,000 times fast-breaking than public-key encryption, solving the problem of slow encryption which asymmetric algorithms suffer from. Public-key encryption provides a solution to key distribut ion and data transmitting issues. Hence, performance and key distribution are improved by combining both approaches without any sacrifice in security.On the othe hand, the PGP process described higher up can be a complex process for users requiring though some training. Apart of awareness it is important both parties to have installed PGP-compatible programs to be able to exchange PGP messages (Benz, 2001).PGP2 ConfigurationPGP2 implements the public key encryption using the RSA and IDEA algorithms to provide secure electronic mail communication either between individuals or known sources (e.g. EDI). This approach of authentication through cryptography ensures that the encrypted message does not provide any information that it is carrying even if it is intercepted by attackers. The recipient of the mail can decrypt the mail using the associated private or public key (Simmons, 1993).This approach verifies that the recipient is certain that the message is from the current sender an d the contents has not been changed or lost during data transmission from sender to recipient. Furthermore, a digital signature can be machine-accessible together with the mail to further confirm the identity of the sender. This approach complements password authentication and is therefore utilized in interpersonal communication between known parties.Similar combination of asymmetric and symmetric encryption techniques can be infer to other application domains involving collaboration between oversize groups. Common prerequisite is to obtain the secret key information in the lead the recipient is able to decrypt the mail.HARDWARE-BASED IMPLEMENTATION OF RSA/IDEA ENCRYPTIONA VLSI implementation of an encryption process, which combines RSA for key exchange and IDEA for block encryption, are proposed in (Buldas and Poldre, 1997). The encryption process consists of 8 rounds. Each around contains 16-bit modular additions and multiplications which simulate the integer calculations used in RSA. Also the key sexual inversion algorithms for both ciphers are similar. When the circuit is in block encryption vogue it starts the IDEA cipher process.One The IDEA cipher applies 128-bit key for block encryption.GnuPG ConfigurationThe aim of GnuPG was to create a digital signature mechanism which would be compatible with OpenPGP but at the same time it should avoid the use of patented algorithms like RSA. GnuPG provides therefore encryption and decryption services based on a range of both symmetric and asymmetric algorithms (Garloff and Jaeger, 2000).Keyring is the key management solution of GnuPG maintaining a database of private keys and a range of corresponding public keysHashing modules verify the authenticity of the public keysWeb of trust a collection of signatures which have been declared as trusted by other users form a web of trusted keysIn comparison to PGP2, GnuPG rejects emais signed with RSA and IDEA keys, potentially been produced by PGP2. And vice versa, PG P2 rejects emails signed with DSA/ELGAMAL keys from GnuPG. GnuPG is compatible with PGP5 (Garloff and Jaeger, 2000).ConclusionIn this paper we illustrated that symmetric and asymmetric techniques in cryptography have their own advantages and disadvantages. Symmetric algorithms are better in performance than asymmetric methods, and require all parties to share a key forward they collaborate. The asymmetric ciphers allow public key infrastructures and key exchange systems, but they consume a lot of processing resources. A hybrid cryptosystem is an approach forward which combines multiple algorithms of different types, in order to exploit the scoop out advantage of each type.One typical approach is to apply a symmetric module to generate a random secret key, and then apply an asymmetric module to encrypt this key using as input the receivers public key. After that, the message is also encrypted using the symmetric algorithm and the secret key. Both the encrypted secret key and the ci phertext of the message are then sent to the receiver.Since it is insufficient to use a single loving of cryptographic algorithm in applications, the hybrid approach in cryptography fills the gap of efficiency or performance of each of the types of cryptography (symmetric, asymmetric) along with the objectives of confidentiality, data integrity, authentication, and trust between two communication parties. This need is generalized to any type of collaboration between individuals (email exchange, group collaboration, file sharing, etc).