Anyone else who sees the message cannot read it, because they have only the public key. The message only makes sense when it gets to me, as I have the only copy of the private key, which does the decoding magic, to turn the zeros and ones bits of information into readable text.
The most common use of PKE for e-commerce involves the use of so-called Digital Certificates issued by "trusted" third parties. Here's how this one works. Say you are a customer of Big Safe Bank and you would like to communicate with your bank. If you sent the bank some information for instance, "please wire the contents of my savings account to a new account in Switzerland" , you might worry that the information could get intercepted en route but you might also worry that the bank would not know it was you who sent the information.
You and Big Safe Bank agree to use a trusted third party to help you communicate in an encrypted manner to one another over the Internet. The bank contracts with VeriSign or another provider of a Digital Certificates.
When you send a message to the bank, you send your message about wiring funds encrypted twice: once with your own private key, and once with the bank's public key, along with a certificate, encrypted using the institution's private key. Once the bank gets your message, they use the institution's private key to decrypt the certificate, which in turn gives the bank your public key. The key in the certificate can decrypt the message you sent to such an extent that all the bank then needs is its own key to read the message.
After all those keys have worked their magic instantaneously, the bank can be certain of two things: that you were the one who sent the message and that the message was not read along the way. And you know that the only one who could have read the message was the bank. The funds get transferred, as requested - probably using another encrypted data transmission. Public Key Encryption ostensibly creates a world in which it does not matter if the physical network is insecure.
Even if - as in the case of a distributed network like the Internet, where the data passes through many hands, in the form of routers and switches and hubs - information could be captured, the encryption scheme keeps the data in a meaningless form, unless the cracker has the private key.
What encryption means? The translation of data into a secret code. Encryption is the most effective way to achieve data security. To read an encrypted file, you must have access to a secret key or password that enables you to decrypt it. Unencrypted data is called plain text ; encrypted data is referred to as cipher text. What are encryption techniques?
Encryption is a security method in which information is encoded in such a way that only authorized user can read it. It uses encryption algorithm to generate ciphertext that can only be read if decrypted.
What is decryption key? Decryption key is the code that you need to transform an encrypted message, document, or other data into a form that can be freely read is decrypted. Security Management. End-to-End encryption. What are the types of encryption? While there are many kinds of encryption - more than can easily be explained here - we will take a look at these three significant types of encryption that consumers use every day. What is the difference between decryption and encryption?
Difference between Encryption and Decryption. Encryption is the process of converting normal message plaintext into meaningless message Ciphertext. Whereas Decryption is the process of converting meaningless message Ciphertext into its original form Plaintext. What is private key used for? A private key is a tiny bit of code that is paired with a public key to set off algorithms for text encryption and decryption.
It is created as part of public key cryptography during asymmetric-key encryption and used to decrypt and transform a message to a readable format. A private key is also known as a secret key. What is RSA encryption? The structure of the plaintext and the suggested security framework consider the fixed structure of the transmitted data and, thus, provide the required degree of security according to this fact.
This agent is responsible for purchasing and security management without interfering with the customer. The rest structure of this study is organized as follows. Section 2 presents related works. Section 3 presents materials and methods. Section 4 describes the results and discussion. Finally, the conclusion of the proposed approach is concluded in Section 5. Many lightweight cryptographic algorithms have been created, as well as existing methods that have been tweaked to accommodate resource constraints.
Reference [ 40 ] discussed data security and compression using the advanced encryption standard AES. They proposed increasing the number of rounds Nr. The initial key has been generated from the Polybius square. This article is based on enhancing security by increasing the number of rounds, which takes more time to calculate time-consuming.
There are no changes to the original work of the AES only increasing the number of rounds to increase complexity which increases security and at the same time increasing execution time. This initiative, led by [ 41 ], focused on data security and compression using advanced encryption standards AES. Such a system keeps the suggested scheme's security level as high as feasible.
Then, the algorithm is executed in 16 rounds. Permutation does not offer a great deal of complexity. The complexity is reduced so much which affects the security that is reduced in turn.
So, this paper increased encryption speed but reduced the security. In [ 16 ], the advanced encryption standard is changed in the study to solve its high computing demand, which is caused by the complicated mathematical processes in Mix Columns transformation, which slows down the encryption process. Because bit permutation is simple to perform and does not require any sophisticated mathematical computation, the updated AES utilized it to replace the Mix Columns transformation in AES.
The encryption time is lowered in this study. Furthermore, the complexity is reduced too much. Pit permutation is used to increase the encryption speed, but it reduced the complexity too much because the complexity of the AES depends on the Mix Column.
In the cipher round, new primitive operations, such as exclusive OR and modulo arithmetic, were added to address the poor diffusion rate in the early rounds, according to [ 20 ]. The key scheduling technique was also enhanced using byte substitution and round constant addition. To assess diffusion and confusion properties, the modified AES was compared to the regular AES using the avalanche effect and frequency test.
The difficulty in this study is based on increased computations, which resulted in a longer encryption time than normal AES. The AES algorithm itself is not modified, but the key scheduling technique is made more complex which produced more complexity. This method starts with a bit plain string as its input. This text has been converted to encrypted text. The FPA is used to generate the keys for the planned task. This improves the security of the proposed work for data transmission over the Internet.
Then, encryption is done. The next step is decryption. In this paper, the AES has not modified itself, but the technique of generating the encryption key is changed depending on the flower pollination algorithm, which consumes additional time and increases only the S-Box complexity, not the entire algorithm. Another study by [ 44 ] proposed and implemented an enhanced modification for the advanced encryption standard AES algorithm using an additional key generated using a linear feedback shift register LFSR , which provides an efficient technique for pseudorandom number generation, as well as a reduction in the number of rounds.
The algorithm complexity depends on key generation using LFSR. No additional randomness is shown. There are no modifications on the AES algorithm but only change in the key scheduling and generating. This study [ 45 ] proposes a secured modified advanced encryption standard algorithm that reduces the number of rounds in the advanced encryption standard AES to 14 to reduce encryption and decryption process time while also enhancing data security. In this study, the encryption time is reduced, but the complexity is reduced too much.
It is obvious from the previous papers that all of them failed to achieve the balance between speed and security. The e-commerce system has witnessed huge extensions in recent years due to the massive and various Internet technologies. This in turn led to great expansions in the size and type of transmitted data across the Internet. Some of the data contain sensitive information that may be exposed to different types of attacks, especially payment information.
Therefore, security must be provided for the transmitted data. As mentioned before, this is about the e-commerce environment, where the transmitted data are characterized with the following features: 1 The information contains financials from which it gains importance ; therefore, it must be protected against any possible intruders and attacks. This is the reason for using symmetric encryption. The transmitted data are arranged and packed into a record called a record form, which is described in Table 1.
The e-commerce website generates a secure environment for data transmission depending on an agent structure that is responsible for two tasks: purchase management and encryption management. The proposed agent can be described in Table 1. The proposed agent is shown in Figure 1.
This means that the record form is generated and encrypted by the agent and then sent to the commercial website. The encryption process is performed according to the proposed encryption algorithm. The proposed algorithm, which is called lightweight AES, is used to transfer data between customers and e-commerce systems over the Internet. It is used to transfer purchase information not payment to prevent any manipulation that can be done by an intruder during transmission.
The AES algorithm is usually used for encrypting data transmission due to its secrecy, complexity, strength, and performance. However, it struggles with huge calculations. Reducing these calculations requires a long time and increases performance and security without reducing the algorithm efficiency.
A modification has been made to the standard algorithm, which will be explained in the following sections, but first, there will be some preliminary steps before starting the encryption process. The plaintext that will be encrypted is a record that is referred to as a form record, as shown previously in Table 1 in Section 3.
The whole process of encryption can be described in Algorithm 1. The input for Algorithm 1 is the order form which contains the details of the customer purchase order.
The plaintext is a sequence of characters letters and numbers that are converted to hexadecimal because it is the typical representation to be processed in AES processes. Before starting the encryption process, there are two steps, which are called preliminary steps. These steps involve the padding process and zigzag algorithm, which are performed on the sender side. These operations are considered preprocessing steps that reduce statistical relations among the string character before encryption.
This is the first process that is applied to the purchase order which is mentioned previously. Here, the string length is 14, and two characters need to be completed to reach the length of Thus, a counter is used to specify the required number.
Two characters are concatenated as expressed in the algorithm. The complexity of the padding step is 2 8 n L , where 2 8 is the length of each character, n represents the plaintext length, and L represents the number of times of repeating the padding process for each plaintext. To increase confusion and diffusion, a zigzag pattern is applied, as shown in Figure 2.
The zigzag pattern can be described as a rearrangement of the characters inside the string to break the statistical relations among them. This pattern is used only one time before the encryption to compensate for the elimination of the substitution step Sub Bytes inside the modified AES algorithm, as will be described later. The result is suitable to be encrypted by the AES algorithm.
The complexity for the zigzag operation is 2 8 16 L , where 2 8 represents the length of each byte in the matrix of the zigzag, 16 represents the total number of cells in the matrix to perform zigzag on, and L represents the number of time of repeating the zigzag operation. In modified AES, to reduce the execution time and the calculation time, several changes are made.
First, the total number of rounds is reduced to 6 rounds. Mix Column operation costs a huge amount of time for the calculations, which is the most important operation that provides complexity and security.
Reducing the number of rounds reduces the total time required to complete the encryption without affecting the security degree of the algorithm. Additionally, eliminating the substitution Sub Byte operation will save more time without affecting the AES performance. However, the zigzag method is used to provide confusion and diffusion because performing the encryption rearranges the characters of the text, but it will be performed only once before starting the AES operations, which means that it will not cost too much time.
Performing the encryption process in this order using these steps provides a fast and secure encryption algorithm that is suitable for securely transforming the information over the Internet.
Providing security and a fast processing time is the main goal of this paper, which is discussed in the experimental results. The shift row step is replaced by a shifting column to make it more difficult for a hacker to predict the manner of operations being performed. Shift column is performed in the same manner as to shift row, but it is performing on columns instead of rows with some modification as described in Figure 3. The first three columns are shifted in the same direction, while the last column is shifted in the reverse direction.
This manner of shifting provides more confusion and diffusion. After the shift column process, the matrix will be as shown in Figure 4 :. The complexity of the shift column operation complexity is 2 5 4 , where 2 5 represents the length of a complete column number of bits to be shifted for each column because each shift is performed for the whole column at a time, and 4 represents the number of columns to be shifted.
Figure 5 describes the details of the round in modified lightweight AES. On the receiver side, the decryption process will be performed in reverse order using the same key as described in Algorithm 5.
The decryption process is the same as encryption but in a reverse manner, as described in Figure 6. In the decryption process, there must be an inverse process for the mix column step and an inverse process for the shift column step, which are performed in the same manner in a different order. The inverse shift column is performed in the same manner as the initial shift column but in reverse order, as shown in Figure 7 , and by using the resulting matrix shown in Figure 4.
After performing the inverse shift column, the matrix will be returned to its original order, as shown before in Figure 3. Algorithm 6 represents the inverse of the shift column step. Inverse zigzag is performed in the same manner as initial zigzag but in the reverse order, as shown in Figure 8.
The inverse zigzag algorithm can be described as follows in Algorithm 7. Experimental results are used to prove the modified algorithm performance. These criteria involve the NIST test, encryption and decryption time, memory usage on file encryption, and file decryption. The files were encrypted to analyze the performance of the modified AES algorithm.
NIST is the most widely used test for utilizing encryption algorithms. Therefore, it is used here to compare the standard AES and the new block cipher algorithm. Specifically, three tests are used for comparison: approximate entropy, run test, and linear complexity.
These tests provided randomness measures for the encrypted test resulting from both standard AES and the new algorithm. The results are shown in Table 2. The results showed that the new method produced more randomness than the standard AES.
It is shown that as average the modified AES is increased by 0.
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