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Hybrid Encryption Technology

Dept. of Computer Science & Engineering2013-2014

Presented By:

Prashant DahakeMtech 1st sem (CSE)

Roll No 20

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ATechnical seminar on

G.H. Raisoni College of Engineering Nagpur

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Guided by

Mr. Y.S .INGLE

overview

Introduction What is hybrid encryption. What is the need of hybrid encryption. Hybrid encryption using DES and RSA. Hybrid encryption using RSA and D-H. Hybrid encryption in electronic document. Conclusion References

Introduction

Security of data is important. Cryptography is used to secure data. 4 main requirements of cryptography are to maintain

data confidentiality data integrity authentication and non-repudiation from

unauthenticated users To protect above properties symmetric or asymmetric cryptography is used.

Continued…

Symmetric key algorithm :- uses same key .

Asymmetric key algorithm : - uses different key.

Use of individual algorithm is still vulnerable .

that’s why researchers came up with technology called it as

“HYBRID ENCRYPTION TECHNOLOGY”

What is hybrid encryption?

Combination of more than one cryptographic algorithm

It incorporates a combination of asymmetric and symmetric encryption

It provides more security.

Hybrid encryption is considered as highly secure type of encryption as long as the public and private keys are fully secure.

What is the Need of Hybrid Encryption Technology ?

Conventional encryption system uses only one key.

If key is disclosed then complete encryption and decryption process becomes vulnerable.

key distribution problem.

To provide greater security and to avoid explicit transfer of secret key we need hybrid encryption system.

Hybrid Encryption using DES and RSA using any symmetric algo and RSA algo

Encryption Steps using Hybrid Crypto System at the Source

Prerequisite :-source has destination public key(PUK)

Inputs: Plain Data Block (PDB) Symmetric Key (SK)

Outputs: Encrypted Data Block (EDB)

Note: EDB contains both the encrypted PDB (denoted by ED) concatenated with encrypted SK (denoted by ESK)

Encryption Steps:

1) Encrypt PDB using SK to get ED.(Note: This can be done using any symmetric-key crypto algorithm like DES and AES)

2) Encrypt SK using destination’s PUK to get ESK. (Note: This can be done using any public key algorithm like RSA)

3) Concatenate ED with its corresponding ESK to get EDB which is sent to the destination.EDB = { ESK , ED }

Decryption Steps using Hybrid Crypto System at the Destination

Prerequisite: Destination has its Private Key (PRK)

Inputs: Encrypted Data Block (EDB)Note: EDB contains both the encrypted PDB (denoted by ED) concatenated with encrypted SK (denoted by ESK)

Outputs: Plain Data Block (PDB)

Decryption Steps:

1) Decrypt ESK using PRK to retrieve SK.

(Note: This should be done using the same public key algorithm which is used at source)

2) Use the retrieved SK as decryption key to decrypt ED to get PDB.

Figure. Block Diagram of hybrid crypto system

Although there is no explicit key transfer in the hybrid crypto system our proposed key exchange works in the manner shown in Fig

Figure. Key transfer using hybrid crypto system

HYBRID CRYPTO SYSTEM USING RSA AND D-H

Steps of this algorithm are as

1. Choose two large prime numbers P and Q. a. Calculate N = P x Q. b. Select public key (i.e. encryption key) E such that it is not a factor of (p-1) and (q-1)

c. Select the private key (i.e. the decryption key) D such that the following equation is true (D x E) mod (P – 1) x (Q – 1) = 1

Suppose R and G is automatic generated prime constants

And put A=E and B=D

2. Now calculate following as public number

X= GA mod R Y= GB mod R

3. Calculate session key with formula

KA = YA mod R , KB = XB mod R

Such that KA = KB = K.

Figure 2: A Hybrid RSA & Diffie-Hellman

RSA

D-H

X

En

Hybrid Encryption in Electronic Document

Electronic document information suffers from disclosed, counterfeited, tampered, repudiated and so on.

To solve the above problem we used hybrid encryption technology using

encryption technology, digital digest, digital authentication and digital signature .

Adobe Acrobat software uses hybrid approaches so single documents can be protected for multiple recipients, each possessing unique key pairs.

The file size is not significantly increased during this method because the entire document does not need to be encrypted for each person.

Instead, the document is encrypted with a single symmetric key and that symmetric key is encrypted for each recipient with their respective public key.

Conclusion

Hybrid encryption technology make use of two different cryptographic algorithm. Which removes the drawback of use of any single cryptographic algorithm and provide double security to secret data .

It removes the key distribution problem

Security systems tends to use a hybrid solution to increase the security and speed of encrypting documents.

References

1. 2012 International Conference on Advanced Computer Science Applications and Technologies. Hybrid Crypto Hardware Utilizing Symmetric-Key & Public-Key Cryptosystems. Adnan Abdul-Aziz Gutub Center of Research Excellence in Hajj. 2. 2012 IEEE International Conference on Computational Intelligence and Computing Research A Hybrid Encryption Algorithm based on RSA and Diffie-Hellman Shilpi Gupta and Jaya Sharma Department of Computer Science & Engineering Amity School of Engineering & TechnologyAmity University, India. 3. 2010 International Conference of Information Science and Management Engineering A Study on the hybrid encryption technology in the security transmission of electronic documents

4. Xin Zhou, Xiaofei Tang, Research and Implementation of RSA Algorithm for Encryption and Decryption, 2011 the 6thInternational Forum on Strategic Technology.

Thank you