Page 69 - IJEEE-2023-Vol19-ISSUE-1

Fareed & Yassin
the same hash. Any text is signed using an SHA-256, and the
output is 256 bits long.
C. CK threat model:
With the Canetti-Krawczyk model (CK), we can formally
develop and analyze the proposed scheme. The proposed
system should have many essential security properties [12].
In this paper, we used the following features:
• Scalability.
• Privacy preservation.
• Mutual authentication
• Attack resistance.
• Communication security.
• Secure ABAC.
IV. THE PROPOSAL SCHEME
The EHR is controlled by health centers instead of
the patients, making it difficult to obtain medical advice from
different health centers. Thus, patients need to concentrate
on getting their health information and medical records back
in order. The development of distributed global database
technology (DGDB) has made it easier for people to obtain
information within medical records. The technology offers
patients access to extensive, consistent reports, with free
access to EHRs from treatment websites or mobile
applications. We will report how we built a security
framework for EHRs with multiple authorities to meet the
need for DGDB in shared EHRs. This method protects
patients' privacy and ensures that EHRs remain unchanged.
This section proposes a secure ABAC authentication
scheme in a healthcare system consisting of two components;
healthcare center (3DD*) and key distribution center (2AD).
Table I contains the necessary symbols used in this paper.
Additionally, our work depends on the initialization phase,
registration phase, and the ABAC phase. The initialization
phase employs 2AD to generate and exchange private and
public keys, which use signing/verifying and
encrypting/decrypting among the main components of the
EHRs message. The registration phase registers a new 3DD*,
which generates the primary keys for the 3DD*. The ABAC
phase is responsible for exchanging, authenticating, and
verifying the EHR of the system's components. These main
phases are explained in detail below.
TABLE I
NOTATIONS.
Notation Descriptions
3DD Healthcare centers
ABAC Distributed Global Database
;3E+# The patient's electronic health record
F*
2AD patient
Key Distribution Center
F<,--# The public key of the health center
F1,--# The private key of the health center
G;HD(. ) Signcryption function
IG;HD(. ) Usigncryption function
? Exclusive-Or
|| Concatenation
| 65
A. Initialization Phase
Step 1. In the initialization phase, the 2AD creates a table
containing all public keys for the 3DD*.
Step 2. Key Initialization
• & = a large prime number, public to all
• ' = a large prime factor of & - 1, public to all
• * = an integer with order ' ,-.78- &, in [1,… , & -
1], public to all
• h01h = a one-way hash function
• 23 = a keyed one-way hash function = 234(,) =
h01h(4, ,)
• (E, D) = the algorithms which are used for encryption and
decryption of a private key cipher. Alice sends a message
to Bob.
B. Registration Phase
The 3DD* achieves registration in the system through the
following steps:
Step1. The 3DD* registers its information in the system (e.g.
Healthcare center name (3DD,.# ), Address (KA* ), Phone
No. (FH*), Email (;L*).
Step2. 3DD* Initializes the database to save the patient's
EHR.
Step3. Public and private keys are generated
(F1,--# , F<,--# ) for the signing/encrypting (signcryption)
data from the 3DD* as shown below:
• 9:!""! = ;# ; where ;# is a private key of 3<<$,
chosen randomly from 1 to ' - 1.
• 97!""! = =# = =*%&" mod p; it represents the public
key of 3<<$.
Step 4. Finally, 3DD* sends (F<,--#,3DD,.#) to the 2AD.
C. Distributed Global Database (MNMO) Phase
In this phase, we give details regarding the patient's
need to visit a healthcare center that is different from their
primary center; the patient's EHR is included. The following
steps describe the primary tasks of this phase:
Step 1. ;3E+# is stored in the 3DD#.
Step 2. F* needs to visit a specific healthcare center that is
not his primary healthcare center.
Step 3. There is a 3DD0 that is near F*.
Step 4. F* needs to visit the nearby 3DD0.
Step 5. 3DD0 requires the ;3E+# from the 3DD#.
Step 6. 3DD0 calculates E ,--$ = (3DD#12) and sends it to
2AD to receive the public key for 3DD#.
Step 7. 2AD receives E ,--$ to retrieve the F<,--$ and
calculate 3F<,--$ = h,-h(F<,--$).
Step 8. 2AD sends (F<,--$, 3F<,--$ ) to 3DD0.
Step 9. 3DD0 receives ( F<,--$, 3F<,--$ ) and calculate
33F<,--$ = h,-h(F<,--$).
Step10. 3DD0 compares (33F<,--$, 3F<,--$) if true, then
computes P = G;HD+4%&&$ (query+#) then go to Step 12.
Step11. Otherwise terminate this phase.
Step12. 3DD0 sends P to 3DD# to receive ;3E+# .