LIGHTWEIGHT PRETTY GOOD PRIVACY EMAIL ENCRYPTION

e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:02/Issue:12/December -2020

Impact Factor- 5.354

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LIGHTWEIGHT PRETTY GOOD PRIVACY EMAIL ENCRYPTION Waseem Ullah Khan*1, Tahir Ullah*2, Hizbullah Khan Jadoon*3, Noor Ul Arfeen*4 *1 2 3 Department

of Computer Systems Engineering (CSE), UET Peshawar, Pakistan. *4Agriculture

University Peshawar, Pakistan.

ABSTRACT The security is a major concern in an electronic mail, it causes a lot of issues when a user attempts to send, forward or receive digital information via the internet. Pretty Good Privacy (PGP) is an encryption software used for signing, encrypting & decrypting electronic mails in order to increase the security of email communications. In PGP, compression is done after encryption. Compression does not give security at all; it merely hides things while encryption secure data. The encrypted data is random and it cannot be compressed.

So, properly encrypted data cannot be compressed. In this paper, we have proposed lightweight PGP encryption in which compression is done before encryption. After implementing the proposed encryption method, the results show better performance regarding time and size of encrypted data.

Keywords: Internet of Things, Security, DTLS, Contiki, Cooja.

I.

INTRODUCTION

Pretty Good Privacy (PGP) is an encryption standard for securing electronic mails [1]. PGP offer following services i.e. Authentication, Confidentiality, Integrity and Non-Repudiation. PGP is a hybrid cryptosystem combines features of both symmetric and asymmetric cryptography [2]. PGP process includes combination of hash function, digital signatures, compression algorithm, symmetric and asymmetric cryptography. Various algorithms are used such as SHA or MD5, RSA or DSA, IDEA or CAST, and ZIP or ZLIB for providing authentication, message integrity, confidentiality and digital signatures as shown in Figure 1.

Fig.-1: PGP Cryptographic Function The various terms discussed in the Figure 1 are discussed below [3],     

H: Hash function is used on message to generate message digest EP: Asymmetric Encryption used for digital signature, encrypted with private key of A II: Concatenation (combines both original message and encrypted message) Z: Compression EC: Symmetric Key Encryption used for confidentiality, message is encrypted using DES or IDEA or CAST-128 with one-time session key

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EP: Asymmetric Encryption using public key of B, session key Ks is encrypted with B’s public key DP: Asymmetric Decryption using private key of B, to recover session key Ks DC: Symmetric Decryption, using session key Ks to decrypt message Z-1: Decompression to get original message along with message digest

The paper is outlined as: Section II describes the literature review. Section III presents the methodology.

Section IV the results are discussed in details. In Section V the conclusion discussed.

II.

LITERATURE REVIEW

Although a lot of research has been carried out in the field of cyber security of email encryption but there is still lot more to do. A brief summary of some developments and futures challenges in email encryption are compiled. We are living in modern era whether we are sending email, booking a hotel/cars and order for a dinner we are costly using the internet, and inherently constantly generating a data. This data is generally stored on the cloud which is basically a huge server that you access online. Also, we have a bunch of devices to access your data. This increase in the use of technology brought with an increase in cybercrimes.

Now for a hacker it’s a golden age that so many access points, public IP addresses and constant traffic and thumbs of data to explode. Hackers are having one hell of a time, exploding vulnerabilities and creating malicious software for the same. About that cyber-attacks are evolving by the data. Hackers are becoming smatters and more creative with the Malwares. For hackers, the possibilities increased exponentially, along with the potential rewards. The fact that cybercrime now effect the very field of society so now the cyber security is crucially important.

In [4], the authors show research on Denial of Service (DoS) in email encryption. DoS refer to an adversary’s attempt to disrupt, subvert, or destroy a network, a DoS attack is any event that diminishes or eliminates a network’s capacity to perform its expected function. Hardware failures, software bugs, resource exhaustion, environmental conditions, or any complicated interaction between these factors can cause a DoS. The paper discusses DoS threats at different layer of wireless sensors network such as jamming and tempering at physical layer, collision at link layer, homing, neglect and greed misdirection, black holes, monitoring, authorization and redundancy at network and routing layer. Flooding and desynchronization at transport layer. The paper proposes two improvements that can minimize the threat of DoS attack. In cryptography, key exchange is a procedure by which cryptographic keys for encryption are exchanged between two parties and those keys are used as a part of some cryptographic algorithms like AES [5]. The sender and recipient can then exchange messages encrypted by those keys. Public key cryptography gives a secured method to exchange secret keys. By using key exchange methods both gatherings can exchange the keys or data in a communication channel so that nobody else other than sender and recipient can understand those. This paper presents Diffie-Hellman key exchange method, which is one of the first public key cryptographic protocols used to exchange and build up secret keys between two gatherings over a frail channel. Diffie-Hellman is a mathematical algorithm that allows two PCs to use the publicly shared key and produce an identical shared secret on both systems, despite the fact that those systems might never have communicated with one another as shown in Figure 2.

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Fig.-2: Diffie Helmen This algorithm, in its early forms, has some weakness like man - in - the - middle vulnerability, but with the evolution of algorithms solutions like the use of digital signatures and other protocol variants were added.

However, the algorithm is not suited for encrypting messages due to the fact that there are expensive exponential operations involved which cannot be used repeatedly. The best application is to use it once for establishing a secret key only.

This paper [6] provide deep overview of several important features of AES algorithm in details and shows evolutionary history of some previous researches and modifications that have done on it also comparing it with other algorithms such as DES, 3DES, Blowfish Advanced Encryption Standard (AES) algorithm is one on the most common and widely symmetric block cipher algorithm used in worldwide. The algorithm follows a particular structure in repetitive steps to encrypt and decrypt sensitive data and is applied in hardware and software all over the world. It is extremely difficult to crack the cypher encrypted by AES algorithm and get the real data .no evidence has been found till date of cracking this algorithm. AES has three different key sizes such as AES 128, 192 and 256 bit and each of this cipher has 128-bit block size. But the short comings of the cipher are that it involves lot of calculations and processing secondly it is a block cipher which means that it performs calculations on blocks of data. Which is not feasible in most email encryption.

III.

METHODOLOGY

When we send data through email then some email attacks may be possible like man in middle attack, pretexting, phishing etc. To prevent data from such attacks, we proposed lightweight PGP framework with some improvements. We used RSA 4096 bit as asymmetric encryption algorithms, SHA-512 as hash algorithm, DES as the symmetric encryption algorithm, and ZIP for compression [7]. Our proposed solution is shown in Figure 3.

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Fig.-3: PGP Proposed Solution Assume that Alice wants to send an email to Bob through PGP encryption [8], so Alice and Bob will generate public and private keys first, public keys of both will be known to each other. At sender side, Alice first get message digest H of plaintext P using SHA-512 hash algorithm, this message digest is then encrypted with private key of Alice using RSA algorithm obtained digitally signed hash E(H), then P are compressed using ZIP algorithm obtained Z(P) and concatenate with E(H), obtained (Z(P) + E(H)). The concatenated message is encrypted with the SecretKey using DES symmetric encryption algorithm [9] obtained E(Z(P) + E(H), Ks), now to send this SecretKey to bob we will encrypt it with public key of bob using RSA algorithm obtained E(Ks), the E(Z(P) + E(H), Ks) and E(Ks) are appended and sent as final message to Bob as shown in Figure 4.

Fig.-4: PGP Encryption Process At receiver side, bob will first decrypt the message with his private key using RSA algorithm to get SecretKey Ks as show in Figure 5. Now by using SecretKey, bob will decrypt the final message, obtained compressed plaintext and digitally signed hash (Z(P) + E(H)). Now we will decompress the Z(P), get original plaintext P. Now to verify whether message digest was signed by Alice, for this purpose we will calculate the message digest of original plaintext P using SHA-512 hash algorithm get the calculated message digest. With Alice’s public key, we will decrypt the digitally signed hash, get the decrypted message digest. To see calculated message digest, and decrypted message digest, they both are same, its means authentication, confidentiality and integrity is affirmed and plaintext was indeed sent by Alice.

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e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:02/Issue:12/December -2020

Impact Factor- 5.354

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Fig.-5: PGP Decryption Process

IV.

RESULTS AND DISCUSSION

Compression reduce size of data. By compression, we can store more data in same space and transmit more data in the same time. Compressed messages are more difficult to cryptanalyze as they have less redundancy.

Compressing data before encryption not only makes for shorter messages to be transmitted or stored, but also improves security by reducing the redundancy in the plaintext and making cryptanalysis harder. Compression before encryption also slightly increases your practical resistance against differential cryptanalysis (and certain other attacks) if the attacker can only control the uncompressed plaintext, since the resulting output may be difficult to deduce. The Figure 6 shows the total time taken of both standard PGP and our proposed lightweight PGP. It shows clearly that our proposed method takes less time during implementation.

Total Time Taken 260

Total Time (ms)

255 250

245 240

Standard PGP

235

Lightweight PGP

230 225 220 Total Time Taken

Fig.-6: Total Time Taken The Figure 7 compares the data size of encrypted message of both standard PGP and lightweight PGP before sending it to the receiver. Lightweight PGP encrypt less data as compared to standard PGP.

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e-ISSN: 2582-5208 International Research Journal of Modernization in Engineering Technology and Science Volume:02/Issue:12/December -2020

Impact Factor- 5.354

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Size of Data after ecnryption 3900 3880

Size of Data

3860 3840 3820 3800

Standard PGP

3780

Lightweight PGP

3760 3740 3720 3700

Size of Data

Fig.-7: Size of Encrypted Data

V.

CONCLUSION

We know that standard PGP encryption technique uses compression after encryption. But it does not affect the overall performance of the message because compression of encrypted data is not effective in any means i.e., size and time may not be reduced. So, our technique proposes the method of compression before encryption.

The technique causes reduction in time and minimizes size of encrypted data. The new method can improve the overall performance by enhanced encryption method. As compressed data is less, so it can speed up the overall process like having less latency and more bandwidth.

VI. [1] [2]

[3] [4] [5] [6]

[7] [8] [9]

REFERENCES

Clara, S. “Introduction to Cryptography.” Network Associates, 1990 Garfinkel, Simson L., David Margrave, Jeffrey I. Schiller, Erik Nordlander, and Robert C. Miller. "How to make secure email easier to use." In Proceedings of the SIGCHI conference on human factors in computing systems, pp. 701-710. ACM, 2005 Callas, Jon, Lutz Donnerhacke, Hal Finney, David Shaw, and Rodney Thayer. "Rfc 4880-openpgp message format." Informe técnico, Internet Engineering Task Force (IETF) (2007).

Ramaraj, E., and Karthikeyan, S.: A New Type of Network Security Protocol Using Hybrid Encryption in Virtual Private Networking. Journal of Computer Science 2(9) (2006) Lala Krikor, Sami Baba, Thawar Arif, Zyad Shaaban,” Image Encryption Using DCT and Stream Cipher”, European Journal of Scientific Research, ISSN 1450-216X Vol.32 No.1 (2009), pp.47-57 Sien, O.B, Samsudin, A., Budiarto, R.” A new image-database encryption based on a hybrid approach of data-at-rest and data-inmotion encryption protocol”, Information and Communication Technologies: From Theory to Applications, 2004.

PGP e-mail protocol security analysis and improvement program Dai Kuobin College of Mathematical and Computer Sciences Huanggang normal University Hubei 438000,China Demijan Klinc_, Carmit Hazayy, Ashish Jagmohan, Hugo Krawczyk and Tal Rabin ,“On Compression of Data Encrypted with Block Ciphers”, http://users.ece.gatech.edu/~demi/docs/dcc09paper.pdf K. Deb, S. Agarwal, A. Pratap, and T. Meyarivian. A fast elitist nondonimated sorting genetic algorithm for multi-objective optimization: NSGA-II. In M. Schoenauer et al., editors, Parallel Problem Solving from nature (PPSN VI), pages 849-858, Berlin, 200. Springer.

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