Symmetric and asymmetric encryption pdf

In cryptography two major types of encryption schemes are widely used. Asymmetric algorithms are usually used to encrypt small amounts of data such as the encryption of a symmetric key and iv. What are the strength and weakness of symmetric and. In symmetric keys encryption or secret key encryption, only one key is used to encrypt and decrypt data. A general comparison of symmetric and asymmetric cryptosystems. If weak key is used in algorithm then every one may decrypt the data. Approved for use since the 1970s, symmetric key encryption algorithms are just one way to keep confidential data secure. May 29, 2018 strength is a vague term, but the applications of both vary. Pdf comparison of symmetric and asymmetric cryptography with. The most secret data being transfer over electrical cable is very. Symmetric encryption incorporates only one key for encryption as well as decryption. Asymmetric encryption was introduced to complement the inherent problem of the need to share the key in symmetrical encryption model, eliminating the need to share the key by using a pair of publicprivate keys. Keys are usually very long and encryption is expensive o rsa encryption is a times slower than typical symmetric algorithms o hard to remember secret key where do you store it. The des ideally belongs to the category of symmetric key.

Difference between symmetric and asymmetric encryption. Asymmetric encryption an overview sciencedirect topics. Comparison of symmetric and asymmetric cryptography with. If you dont understand encryption then you are unknowingly inviting hackersyes hackers. Process of encryption depends on the algorithm and the key used to encrypt the data. The key should be distributed before transmission between entities.

Foundations of computer security university of texas at. Pdf comparison of symmetric and asymmetric cryptography. Difference between symmetric and asymmetric encryption with. The two widely accepted and used cryptographic methods are symmetric and asymmetric.

In this type, the encryption and decryption process uses the same key. Besides this, there is a theoretical performance analysis and comparisons of symmetric and asymmetric cryptography. Pdf symmetric and asymmetric encryption ojikutu kayode. This paper comprises of brief description of rsa and des cryptography algorithms and their existing vulnerabilities along with their countermeasures. These keys are regarded as public key and private key.

Symmetric encryption uses a single key that needs to be shared among the people who need to receive the message while asymmetrical encryption uses a pair of public key and a private key to encrypt and decrypt messages when communicating. Asymmetric encryption uses two keys to encrypt your plain text. Sep 06, 2016 principal among these are symmetric and asymmetric encryption. It requires far more processing power to both encrypt and decrypt the content of the message. Dec 31, 2015 symmetric encryption is an old technique while asymmetric encryption is relatively new. In asymmetric also called publickey encryption, one key is used for encryption and another for a symmetric key cryptographic algorithm ayushi lecturer, hindu college of engineering. Fundamentally, there are two types of cryptographic techniques symmetric and asymmetric. As an example of this, consider comparing the required key length, in bits, between a symmetric encryption and an asymmetric encryption.

The following chart is from the nist publication key management guideline, draft, dated nov 12, 2001. About digital certificates to use asymmetric encryption, there must be a way for people to discover other public keys. Symmetric and asymmetric cryptography tutorialspoint. In an asymmetric system, each user has a publicprivate key pair. In an asymmetric cryptosystem or public key cryptosystem, there are two different keys used for the encryption and decryption of data. Asymmetric encryption consists of two cryptographic keys. Encryption is the process of taking a message and scrambling its contents so that only certain people can look at whats inside. Simmons sandm laboratories, albuquerque, new mexico 87185 all c r y p t o s y s t e m s currently m. For securing the data there are two main types of cryptography algorithm, one is called symmetric and other is called asymmetric algorithms. For security reasons, this message is then coded using a cryptographic algorithm. Symmetric private and asymmetric public keys encryption. Take a look at the different algorithms, from des to aes and their spinoffs. The keys may be identical or there may be a simple transformation to go between the two keys. On the other hand, asymmetric encryption uses the public key for the encryption, and a private key is used for decryption.

Using symmetric encryption, security requires that each pair of users share a secret key. Therefore, implementing symmetric cryptography particularly with hardware can be highly effective because you do not experience any significant time delay as a result of the encryption and decryption. In a large network using symmetric encryption many key pairs will proliferate, all of which must be securely managed. In symmetric cryptography, the length of the keys which is randomly selected are typically set at. Request pdf study on symmetric and asymmetric cryptographic techniques data security is the challenging issue in todays world that touches many areas using computer communication. Its security is weakened by the need to exchange a key between both parties. Nov 09, 2017 symmetric encryption is a method of cryptography where a single key is responsible for encrypting and decrypting data. Study on symmetric and asymmetric cryptographic techniques. Typically, an individual performing asymmetric encryption uses the public key generated by another party. The main features of symmetric cryptography are as follows.

To acknowledge some more differences between symmetric and asymmetric encryption have a look at the comparison chart shown below. Ambedkar university, agra for the degree of doctor of philosophy by mr. Symmetric encryption is significantly faster than asymmetric. Introduction to symmetric and asymmetric cryptography. Rsa encryption, used in asymmetric encryption such as pgp, is noted. In asymmetric key cryptography, plaintext and ciphertext note3 10. Symmetric and asymmetric encryption introduction princeton. The most immediate application of sse is to cloud storage, where. A technique with a history that stretches back to the predigital era, symmetric or secret key encryption relies on the use of a secret key which is known to both the recipient and the sender of a scrambled communication.

Two types of encryption symmetric encryption asymmetric encryption asymmetric encryption was created to solve the problem brought about by symmetric encryption. Symmetric encryption is a simple technique compared to asymmetric encryption as only one key is employed to carry out both the operations. The advantage of using symmetric encryption and only using public key cryptography for the symmetric key is performance. This single key is used for both encryption and decryption. If weak key is used in algorithm then everyone may decrypt the data. Another difference between asymmetric and symmetric encryption is the length of the keys. Asymmetric encryption is an encryption technique that uses a different key to encrypt and decrypt the information. This came to the arena to address an inherent problem with the symmetric cipher. Security of symmetric encryption against mass surveillance.

The involved parties share that key, password, or passphrase, and they can use it to decrypt or encrypt any messages they want. Symmetric key algorithms are sometimes referred to as secret key algorithms. Symmetric cryptography versus asymmetric cryptography in symmetric key cryptography, symbols in plaintext and ciphertext are permuted or substituted. By using a different key, this prevents someone from creating a decryption key from the encryption key and helps the encrypted data stay even more secure.

If you dont understand encryption then you are unknowingly inviting hackersyes hackers who are there to steal all your businesscritical informationhackers who deploy ransomware attacks. On the down side, symmetric key cryptography requires that the secret key be securely exchanged and then remain secret at both ends. What is asymmetric cryptography and how does it work. This is because these types of algorithms generally use one key that is kept secret by the systems engaged in the encryption and decryption processes. Advantages and disadvantages of asymmetric and symmetric cryptosystems cryptosystems can be of two types. A problem with asymmetric encryption, however, is that it is slower than symmetric encryption. As a result, asymmetric encryption is normally reserved for the encryption of symmetric keys or data that is infrequently encrypted or decrypted. Asymmetric encryption is also known as public key cryptography which is a relatively new area compared to symmetric encryption. Some problems in symmetric and asymmetric cryptography. Advantages and disadvantages of asymmetric and symmetric.

In it, instead of a single key, every person has a pair of keys. A closer look at symmetric versus asymmetric encryption. Asymmetrical encryption is also known as public key cryptography, which is a relatively new method, compared to symmetric encryption. Symmetric key algorithms are algorithms for cryptography that use the same cryptographic keys for both encryption of plaintext and decryption of ciphertext. The rsacryptoserviceprovider class is provided by the. In this chapter, let us discuss in detail about symmetric and asymmetric cryptography. Symmetric key algorithm an overview sciencedirect topics. Asymmetric cryptography in symmetric key cryptography, symbols in plaintext and ciphertext are permuted or substituted. Security of symmetric encryption against mass surveillance mihir bellare1, kenneth g. Dynamic searchable symmetric encryption seny kamara charalampos papamanthou y tom roeder z abstract searchable symmetric encryption sse allows a client to encrypt its data in such a way that this data can still be searched.

Certificate this is to certify that the thesis entitled some problems in symmetric and asymmetric cryptography submitted to dr. Asymmetric key cryptography is appropriate for short. Performance evaluation of symmetric encryption algorithms. Asymmetric encryption provides superior encryption when compared to symmetric encryption. Symmetric vs asymmetric encryption difference explained. Sep 06, 2016 the fundamental difference that distinguishes symmetric and asymmetric encryption is that symmetric encryption allows encryption and decryption of the message with the same key.