Case study 1:
Brute force attack: A brute force attack is considered as a method of gaining access to a system, network, or computer by using a series of passphrases and passwords until the correct password is matched (Stiawan et al. 2019). The process is lengthy, and hence there is a process of decrypting the password key by using a key derivation function. That process is called an exhaustive key search. Such a task is tedious and is usually implemented when there are no other alternatives or weakness left to exploit. They are quick only when the passwords are short, but in long passwords where the permutations and combinations are more the time taken increases exponentially. Thus in those cases, dictionary attacks are usually used (Gillela,Prenosil and Ginjala 2019).
In these types of attacks, the hacker or the intruder tries to obtain the right key by trying all the combinations of keys. Hence, 2n-1 number of trials can be used in this case. Moriarty, who is the culprit, in this case, could make use of the employees for obtaining the ciphertext (Li, Shi and Zhang 2017). The plain texts are easier to obtain as they are unencrypted and unprotected.
| Number of possible character combinations:(Password Type)^(Password Length)Where the password type is the number of possible characterEffective Cores:1/((1-Efficiency Constant)+(Efficiency Constant/Processor Cores))Where, the efficiency constant is 0.99 Processor GFLOPS:Processor Frequency * Effective CoresKeys Per Second:GFLOPS/Encryption ConstantTime in seconds:Seconds = Combinations/KeysPerSecond |
However, for launching an attack, the hacker needs some idea about the plain text, like the format in which is stored, or is the plain text just limited to the numbers or is it alpha-numeric and a few things. Ths without completely processing the plain text, decryption of the entire is possible.
Compressing the text along with the encryption can be very effective for the entire system, this is because, encryption of the larger file can help in protecting the data, but compressing them helps in providing extra security as the intruder will not be completely aware of the size of the text making the task of obtaining and manipulating the data much more challenging.
Again, Watson’s suggestion cannot be declined completely. If there is any way in which the files can be secured without compression is by encrypting them end to end. One of the major drawbacks of the compression process is the processing time. In simple language, larger files take more time to compress. Thus, encryption is beneficial, as well.
The bank has chosen OFB over the CBC for enhancing their protection. OFB or the Output Feedback is much more beneficial that the Cipher Block Chaining or the CBC due to its ability to encrypt multiple sizes and block cipher data with the help of output key generated from the feedback.
DES or the Data Encryption Standards suggested by Holmes, along with another DES key, has special significance. This method is also termed as the triple-DES method. That is, the encryption is even stronger (Alhag and Mohamed 2018). Here the encrypted data are re-encrypted with the help of the symmetric key block cipher. Even after the application of the triple-DES, Moriarty will need 2n-1 where n is the possibility of the attack. However, now he will require more than just the pain text (Dey et al. 2019). He has to gain access to atleast one of the keys, which will be more challenging.
Case Study 2:
After performing a detailed analysis of the case study, it can be said that Dr. Watson’s suggestion for the development of an encryption technique for the protection of the data is extremely beneficial. With the help of the encryption techniques, the integrity of the message will remain, and the sender and the receiver of the texts can be well assured of the fact that the text is sent by the original senders. The past history of the organization shows data breach and loss of data making it extremely necessary to implement the data encryption techniques.
Key revocation is regarded as the manner of permanently retiring PGP public keys. Key revocation is a certificate which is suggested to be generated immediately after pairing of the keys is done. It is a revoked copy of a public key, which can be very beneficial if the passphrase of a private key is forgotten and needs to be revoked or disabled. It is very difficult because it has a lot of formalities. A trusted third party is required for its creation, and it is also vulnerable to malware attacks. Hence, the certificate of key revocation should be released soon after the pair of keys is generated. This reduces the chances of a data breach due to the delay in encryption. The company history suggests that the previous loss in the data and other difficulties were caused due to the delay in the certificate release, increasing the time required for the encrypting of the data.
According to Watson, the current encryption process can be beneficial as it makes use of the encryption key to encrypt data before sending, which can only be decrypted with the help of the decryption key. This process makes the entire message exchange process secure.
Apart from this, Triple-DES, along with Advanced Encryption standard, can help in improving the current scenario as well.
There is a difference between digital signatures and decryption of data. It is comparable to a manual signing of a document by using ink and pen and opening of a padlocked box using a key (Rivest and Shamir 2019). Digital signatures include a hash function applied directly to the message and have a verification process completely different from the decryption method. In decryption, there is a post-processing function OAEP post, which is applied to a post after the RSA function.
A masquerade attack can be regarded as a method of gaining unauthorized access to a system, computer, and personal information but in such a way that it appears legitimate. This type of cyber attack makes use of a fake identity, which may be any network or security identity (Wardega, Tron, and Li 2019). This allows them to gain access to personal computers and sensitive information, but the access identification is legitimate and almost authorized by the user himself or herself. A masquerade attack can be generated and triggered in an organization by a member of an organization or an outsider if the network is connected to any public network.
A replay attack is also referred to as a playback attack. It can be defined as a network attack in which the transmission of valid data can be stopped, delayed, or prevented by either the originator or by a person intercepting those data and retransmitting them after some modifications (Lavrentyeva et al. 2017). It could also be an attack on the security protocol in which the original message is overridden by a false replay of messages hiding the true contents. It may fool the users about the authenticity of their work.
The attack that can enable Moriarty to read the conversations between Alice and Bob is a Man-in-the-Middle attack. This attack enables the attacker to masquerade as one of the authorized users. That is, Alice will definitely receive messages from Bob, and Bob will receive messages from Alice as well, but the authenticity of the message will completely be destroyed along with the privacy of their conversation. Moriarty is free to manipulate the messages and gather important data from the conversation as well with the help of sniffing and spoofing attacks. Alice will have no way to understand what is going on, cause they will be in a dilemma that they are receiving authentic messages from each other.
In order to prevent this attack from taking place, strong encryption protocols have to be maintained along with stronger credentials for logging to the network. Installation of strong WEP or WAP Encryption on the Access Points can keep away the people from sharing the same network, thereby preventing the chances of the Man in the Middle attack. Apart from this, the public key-based authentication can help in ensuring each and every stage of the communication is secured. All these can be used for the prevention of the MITM attacks in the system.
References:
Alhag, N.M.M. and Mohamed, Y.A., 2018, August. An Enhancement of Data Encryption Standards Algorithm (DES). In 2018 International Conference on Computer, Control, Electrical, and Electronics Engineering (ICCCEEE) (pp. 1-6). IEEE.
Dey, K.N., Golui, S., Dutta, N., Maji, A.K. and Pal, R.K., 2019, June. Plain Text Encryption Using Sudoku Cipher. In International Conference on Intelligent Computing and Communication (pp. 23-31). Springer, Singapore.
Gillela, M., Prenosil, V. and Ginjala, V.R., 2019, January. Parallelization of brute-force attack on MD5 hash algorithm on FPGA. In 2019 32nd International Conference on VLSI Design and 2019 18th International Conference on Embedded Systems (VLSID) (pp. 88-93). IEEE.
Lavrentyeva, G., Novoselov, S., Malykh, E., Kozlov, A., Kudashev, O. and Shchemelinin, V., 2017, August. Audio Replay Attack Detection with Deep Learning Frameworks. In Interspeech (pp. 82-86).
Li, J., Shi, Y. and Zhang, Y., 2017. Searchable ciphertext‐policy attribute‐based encryption with revocation in cloud storage. International Journal of Communication Systems, 30(1), p.e2942.
Rivest, R.L. and Shamir, A., 2019. 9. A Method for Obtaining Digital Signatures and. Secure Communications And Asymmetric Cryptosystems, p.217.
Stiawan, D., Idris, M., Malik, R.F., Nurmaini, S., Alsharif, N. and Budiarto, R., 2019. Investigating Brute Force Attack Patterns in IoT Network. Journal of Electrical and Computer Engineering, 2019.
Wardega, K., Tron, R. and Li, W., 2019, May. Masquerade attack detection through observation planning for multi-robot systems. In Proceedings of the 18th International Conference on Autonomous Agents and MultiAgent Systems (pp. 2262-2264). International Foundation for Autonomous Agents and Multiagent Systems.
