Performance Of Encryption And Decryption In Php Computer Science Essay


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A lot of researchers were performing research towards the data security , this paper were performing attention towards the CrptoSys API in .net . Performance of encryption and decryption has been analyzed on file of different size, and result shows which algorithm is fast in CryptoSys API.


Data security and exchange of information is getting a lot of importance because of threats over the web, there must be a secure method for the secure exchage of information methodology which protects against threats .

This paper gives the overview of the CryptoSys API and gives the overview and features regarding its encryption and decryption methodology .

Cryptography : Overview

Cryptography is usually referred to as "the study of secret", while nowadays is most attached to the definition of encryption. Encryption is the process of converting plain text "unhidden" to a cryptic text "hidden" to secure it against data thieves. This process has another part where cryptic text needs to be decrypted on the other end to be understood. Fig.1 shows the simple flow of commonly used encryption algorithms.

Cryptography Goals:

This section explains the five main goals behind using Cryptography. Every security system must provide a bundle of security functions that can assure the secrecy of the system.

These functions are usually referred to as the goals of the security system:

Authentication: This means that before sending and receiving data using the system, the receiver and sender identity should be verified.

Secrecy or Confidentiality: Usually this function (feature) is how most people identify a secure system. It means that only the authenticated people are able to interpret the message (date) content and no one else.

Integrity: Integrity means that the content of the communicated data is assured to be free from any type of modification between the end points (sender and receiver). The basic form of integrity is packet check sum in IPv4 packets.

Non-Repudiation: This function implies that neither the sender nor the receiver can falsely deny that they have sent a certain message.

Service Reliability and Availability: Since secure systems usually get attacked by intruders, which may affect their availability and type of service to their users. Such systems should provide a way to grant their users the quality of service they expect.

Block Ciphers and Stream Ciphers:

One of the main categorization methods for encryption techniques commonly used is based on the form of the input data they operate on. The two types are Block Cipher and Stream Cipher. This section discusses the main features in the two types, operation mode, and compares between them in terms of security and performance.

Block Ciphers:

In this method data is encrypted and decrypted if data is in from of blocks. In its simplest mode, you divide the plain text into blocks which are then fed into the cipher system to produce blocks of cipher text.

Fig. 2

Stream Ciphers:

Stream cipher functions on a stream of data by operating on it bit by bit. Stream cipher consists of two major components: a key stream generator, and a mixing function.

Fig. 3

Modes Of Operation:

This section explains the two most common modes of operations in Block Cipher encryption-ECB and CBC-with a quick visit to other modes.

There are many variances of block cipher, where different techniques are used to strengthen the security of the system. The most common methods are: ECB (Electronic Codebook Mode), CBC (Chain Block Chaining Mode), and OFB (Output Feedback Mode). ECB mode is the CBC mode uses the cipher block from the previous step of encryption in the current one, which forms a chain-like encryption process. OFB operates on plain text in away similar to stream cipher that will be described below, where the encryption key used in every step depends on the encryption key from the previous step.

Symmetric and Asymmetric Encryption:

Data encryption procedures are mainly categorized into two categories depending on the type of security keys used to encrypt/decrypt the secured data. These two categories are: Asymmetric and Symmetric encryption techniques.

Symmetric Encryption:

In this type of encryption, the sender and the receiver agree on a secret (shared) key. Then they use this secret key to encrypt and decrypt their sent messages. Fig. 4 shows the process of symmetric cryptography.

Fig .4

Asymmetric Encryption:

Asymmetric encryption is the other type of encryption where two keys are used. To explain more, what Key1 can encrypt only Key2 can decrypt, and vice versa.

CryptoSys API overview:

The CryptoSys API provides functions to carry out primitive cryptographic operations intended to be used as part of a security-related application. It is up to you the programmer to ensure that keys, passwords and other private data in your application are kept secret, and to ensure that appropriate security policies and procedures are followed by end users.

The CryptoSys API is a developer's toolkit of fast, efficient symmetrical cryptographic functions in Visual Basic, VBA, VB.NET/VB2005/8, C/C++, C#, and ASP. You can incorporate it in your own apps and it can be called from VBA applications like Access, Excel and Word. It provides four of the major block cipher algorithms, a stream cipher algorithm, key wrap, secure message digest hash algorithms, the HMAC message authentication algorithm, the CMAC algorithm, a data compression facility, a password-based key derivation function (PBKDF2), a secure random number generator and other utilities. If you need to do "asymmetric" public key cryptography, look at our alternative product CryptoSys PKI Toolkit.

The CryptoSys API functions allow you to encrypt, decrypt, hash and authenticate data in a variety of formats, as well as generating secure random keys to use in your applications. Your input data can generally be in a byte array, encoded as a hexadecimal string, or in a file. The functions can process the data in a one-off manner, or, for longer inputs, you can call the "update" functions sequentially after initialising. The block cipher algorithms work in Electronic Codebook (ECB), Cipher Block Chaining (CBC), Cipher Feedback (CFB), Output Feedback (OFB) and Counter (CTR) modes. You can generate random keys and nonces in a secure manner. All functions are thread-safe.

Future Work and Open Issues

Still There are many API available for the researcher’s to evaluate the performance of encryption and decryption and have to suggest which one is best. Yet new versions of API may have good features for performance.


Thus CryptoSys API provides a lot of good features in different programming languages for the end user in order to make the communication more efficient by removing the threats chances and making the way more secure.

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