166

M. Bakro et al.

Size of file is 30 MB = 30,720 KB

Size of block

(KB)

Count of block

Size of block

(KB)

Count of block

250

30,720/250 = 122.88 = 123

10000

30,720/10000 = 3.072 = 4

1000

30,720/1000 = 30.72 = 31

13000

30,720/13000 = 2.363 = 3

5000

30,720/5000 = 6.144 = 7

25000

30,720/25000 = 1.22 = 2

The same results that we obtained as a result of the experiment

The results demonstrated the ability of the proposed system to maintain data

security at significant levels, in addition to its ability to overcome other types of

threats:

1. A middle man attack (MITM):

The threat occurs between the two communication parties who are users and the cloud

service provider CSP, where the intruder impersonates the other party to persuade the

remaining parties to send messages to him directly in order to tamper with the data

and steal it, but within our proposed system that attack will not succeed because the

data had been encrypted via AES, As for key management using ECC, hijackers will

not be able to return the encrypted data to its original form. In addition, authentication

in blockchain technology between the two sides of the connection will achieve data

integrity.

2. Distributed Denial of Service (DDoS):

Malicious Trojan horses use this attack to destroy system resources, this attack is

very common, but through our proposed system that attack will not succeed due to

the distributed blockchain architecture.

3. Cloud Service Provider (CSP):

CSP that stores data of the user will be able to view it and may use it for unauthorized

purposes or even sell it to some other company without the customer’s knowledge,

so our proposed system consisting of mixed encryption algorithms will not allow the

cloud provider to see the data because it will be in an unreadable encrypted mode,

thus our goal in maintaining data security has been achieved.

Our proposed model that includes encrypting data in the SaaS layer and then

sending it to data centers in IaaS layer that use blockchain technology will maintain

data security and will ensure that:

• Confidentiality: via cryptography algorithms (AES, ECC), they have been used

with the blockchain to ensure the security and confidentiality of data within the

nodes of the chain so that no attacker can change the data, and thus no change on

value for corresponding hash to protect against any penetration.

• Integrity: via hashing algorithms (SHA-256) in blockchain structure.