International Core Journal of Engineering 2020-26 | Page 74

x The algorithm applies only to relational databases.
guarantee access to encrypted data; the proposal offers levels
of scalability and availability of services [17], for to share the
data located in a database, the authors propose Mylar, which
distributes an encryption key to the users; for to prevent a
pirate from tricking users, Mylar includes a browser extension
that verifies the code downloaded from the server; they also
included an identity provider service, who is a web
certification authority; they used the proposal to ensure a
variety of web applications, in the experiments increases the
calculation time by 17 percent on average; is implemented at
Newton Wellesley Hospital in Newton, Massachusetts, to
help protect patients privacy [18], for to improve CryptDB,
which is a database encryption model, the authors worked
with the same Application Server, Proxy Server and DBMS
Server architecture; they replaced the AES and BlowFish
algorithms with the use of Format Preserving Encryption FPE,
which preserves the length and format of plain text when
encrypted; the project was called FP-CryptDB; over the
encrypted data they used Random and Deterministic; the
results of the tests in storage, obtained a 50 percent efficiency,
the performance takes less time of execution [19], for to
protect the database in the cloud, the authors propose to add
indexing information to the table of the database and store
them with the encrypted tables; where the DBMS use the
indexing data; a data partition method defines the attributes
that are used in all queries and also employs four techniques
for data partitioning; frequency, space, three bisection,
histogram [20], the authors propose a method of logical
simplification to raise the performance of the 3DES algorithm,
they updated the algorithm’s critical path through XOR to
take them to a non-critical path; they reached up to 3.33Gbps
in performance [21].
x Encryption is for plain text and at the level of columns
in the tables for the database.
x The result will be an encrypted database in a
distributed environment and supports SQL operations:
delete, insert, select, update.
x To adopt a 3-level architecture.
x To adopt encryption and decryption algorithms to
apply to: request, response, SQL operations and
database.
In the basic scheme, architecture and algorithms were
adopted as explained below:
x The 3-level architecture of [19] was adopted, and they
are: Application Server, Proxy Server and DBMS
Server.
x The 3DES encryption algorithm of [21] was adopted,
to encrypt the request to the database and decrypt the
response of the database, within the Proxy Server
level.
x The SQL-based encryption algorithm of [17] was
adopted, to guarantee confidentiality and SQL
operations on the data encrypted in the database, are
the following: Random (Rand), Deterministic (Det),
Order Preserving Encryption (OPE), Homomorphic
Sum (Sum), Search and Plain; within the DBMS
Server level.
x The FPE algorithm of [19] was adopted, for the
encryption of the database within the DBMS Server
level.
B. Methods
A basic scheme was proposed to manage the security of
DDB, with the following scope:
The Fig. 1 describes the request, processing and response
of data:
x Define an abstract algorithm.
Fig. 1. Proposal of basic security scheme for a DDB.
request to the proxy server.
III. R ESULTS
It resulted an algorithm through flowchart techniques in
Fig. 2. The general steps of the algorithm are described below:
2) The proxy server encrypts the received request.
3) The proxy server sends the encrypted request to the
DBMS server.
1) The user through an application server, sends his
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