This document summarizes two authentication algorithms for smart grids. Algorithm 1 describes authentication between a cloud, reader, and smart meter. It uses digital signatures and timestamps to prevent replay and man-in-the-middle attacks. One-time session keys provide forward secrecy. Algorithm 2 uses bilinear pairings for registration and authentication between two entities. It achieves security goals like preventing replay attacks through timestamps, ensuring message integrity with signatures, and providing private key privacy and perfect forward secrecy through its key establishment method. Both algorithms aim to securely authenticate communications in smart grids.

1. Authentication in Smart Grid
(Part 4)
PRESENTED BY:
SHERIF ABDELFATTAH
1
ECE department
sabdelfat42@students.tntech.edu

2. Introduction
•Smart meters (SMs) now a days are widely used for demand and supply management in SGs.
•It needs to communicate with other entities in the network system. So, there is a need for a secure
communication system that can ensure a secure information exchange between the legal entities
while maintaining its privacy.
•Thus, authentication become critical security component in the smart metering infrastructure (SMI)
which provides privacy preservation in order to provide reliable power services to the SG.
•Authentication is the process that ensures that the communication occurs between two legitimate
entities by verifying their identities.
•of the smart grid communication network can affect the availability, reliability, safety, and
productivity of the power system.
•There is some security issues that can effect on the privacy of the users. Also, because of the high
dependency on communication and networking systems makes the SG infrastructure vulnerable to
different threats. These threats include the potential for several types of cyber-attacks, such as man-
in-the-middle (MinM) attacks, impersonation attacks, replaying, and injecting messages.
2

3. Introduction
Why is this topic important
•To ensure the security of two-way communication between smart grid entities, authentication
and key establishment is a necessary, which enables the entities to verify the legitimacy of the
entity with which they communicate, and to build a shared key with the legitimate entity for
further communication.
•The user needs to authenticate the utility company or its representing node to protect his
privacy by ensuring that his consumption is sent to the right place.
•The utility company needs to authenticate the user to save the network from any malicious user
that can send false data to affect the network performance or shut it down.
•For example, an attacker may change the user’s power consumption readings sent to the utility
by a smart meter, which can lead to wrong decision-making by the control center.
3

4. Common Challenges
•Security against cyber-attacks like eavesdropping, replay attacks, man-in-the-middle (MitM)
attacks, and impersonation attacks.
•Ensure the integrity of the message while the authentication process.
•Lightweight authentication are needed due to the limited computation resources of the smart
meters.
•Decrease computation and communication overheads.
•Mutual authentication.
•Session key agreement.
4

5. Common Attacks
•Eavesdropping: Eavesdropping is an attack to capture the unauthorized information that is
confidential.
•Replay attack: The external adversary 𝒜 captures the previous message and replays the out-of-
date messages to gateway.
•Brute-Force Attack: Brute-force attack is to try every possible key on a piece of cipher text until
an intelligible translation into plain text is obtained.
•Man-in-the-Middle Attack: A Man-In-The-Middle (MITM) attack is the attack in which the
attacker pretends to be the right person during the communication and uses the information
received from one side to fool the other side. Both sides of victims feel that they are exchanging
information directly.
5

6. Common Attacks
•Impersonation Attack: A device attack aims to impersonate a legitimate device, such as a smart
meter.
•Internal Attack: An internal attack happens when an attacker is from the organization or has the
assets that can help him to access the unauthorized resource.
•Forward Secrecy: Forward secrecy ensures that even if one session key gets compromised, other
session keys can not be compromised.
•Denial-of-Service Attack: an attacker attempts to prevent legitimate users from accessing
information or services, by targeting the hosting devise
6

7. Preliminaries - Bilinear Map Pairing
Let 𝐺1, 𝐺2 and 𝐺𝑇 be cyclic group of prime order 𝑞.
Let 𝑃1 is a generator of 𝐺1 and 𝑃2 is a generator of 𝐺2.
Let 𝑒 be a map 𝑒: 𝐺1 × 𝐺2 → 𝐺𝑇 which is called a pairing
The Bilinear pairing has the property that for all 𝑃 ∈ 𝐺1, 𝑄 ∈ 𝐺2 and all 𝑎, 𝑏 ∈ 𝑍 we have 𝑒 𝑎𝑃, 𝑏𝑄 =
𝑒 𝑃, 𝑄 𝑎𝑏.
▪ 𝑒 𝑎𝑃, 𝑏𝑄 = 𝑒 𝑎𝑏𝑃, 𝑄 = 𝑒 𝑃, 𝑎𝑏𝑄 = 𝑒 𝑃, 𝑄 𝑎𝑏
= 𝑒(𝑏𝑃, 𝑎𝑄)
▪ 𝑒 𝑃 + 𝑃1, 𝑄 = 𝑒 𝑃, 𝑄 𝑒(𝑃1, 𝑄)
▪ 𝑒 𝑃, 𝑄 + 𝑄1 = 𝑒 𝑃, 𝑄 𝑒 𝑃, 𝑄1
▪ 𝑒 𝑃 + 𝑃1, 𝑄 + 𝑄1 = 𝑒 𝑃, 𝑄 + 𝑄1 𝑒 𝑃1, 𝑄 + 𝑄1 = 𝑒 𝑃, 𝑄 𝑒 𝑃, 𝑄1 𝑒 𝑃1, 𝑄 𝑒 𝑃1, 𝑄1
▪ If 𝑒 is symmetric then 𝑒 𝑃, 𝑄 = 𝑒(𝑄, 𝑃)
7

8. Algorithm 1 [1]
There are usually two types of smart grid devices, networked and isolated.
▪ The networked smart grid devices are a part of a smart grid data communication network.
▪ The isolated smart grid devices exist in the area that is not covered by a smart grid communication
network. Isolated devices are resulted from many causes including agreement between the electricity
user and the utility company, and cost-effective considerations not to cover faraway devices.
8
[1] Sha, Kewei, Naif Alatrash, and Zhiwei Wang. "A secure and efficient framework to read isolated smart grid devices." IEEE Transactions on Smart Grid 8, no. 6 (2016): 2519-2531.

9. Algorithm 1
•Network Model
Three parties, the electricity service provider cloud (referred as cloud), the reader, and the smart
grid device.
1. Request: the Kth round of data reading request is issued by the reader to the smart grid device.
2. Replay: smart grid device then responds by sending its ID in a message {Mid, TMSP}SKk-1 , where
Mid is the smart grid device ID and TMSP is the timestamp of this message
9

10. Algorithm 1
•Challenges
1. An eavesdropper may listen on the communication channel between the smart grid device
and the reader.
2. A fake device reader may be used to read the data from the smart grid device.
3. Someone who is not working in the company may take a reader to read data.
4. A worker who is not assigned the task, but tries to use a reader to read the data from meter.
5. The smart grid device may be modified to provide incorrect data.
10

11. Algorithm 1
•Security Goals
To work against these attacks
1. Eavesdropping
2. Brute-Force Attack
3. Man-in-the-Middle Attack
4. Device Attack
5. Internal Attack
6. Replay Attack
7. Forward Secrecy
8. Denial-of-Service Attack
11

12. Algorithm 1
Notation Description
Rid reader ID
TR
reader’s request timestamp
Key one-time session key
Pri(R) reader’s private key
Pub(C) cloud’s public key
C cloud ID
Uid worker ID
12
•Authentication process.
Between the cloud and the reader

13. Algorithm 1
13
•Authentication process.
Between the reader and the smart meter

14. Algorithm 1
14

15. Algorithm 1
Eavesdropping. all communications
are encrypted to prevent
eavesdropping.
Security Goal 1
Brute-Force Attack. using modern
cryptographic algorithms like AES,
the basic brute-force attacks have
been proved to be blocked by using
appropriately sized keys like 256-bit
keys.
Security Goal 2
15

16. Algorithm 1
Eavesdropping. all communications
are encrypted to prevent
eavesdropping.
Security Goal 1
Brute-Force Attack. using modern
cryptographic algorithms like AES,
the basic brute-force attacks have
been proved to be blocked by using
appropriately sized keys like 256-bit
keys.
Security Goal 2
Man-in-the-Middle Attack. an
MITM attacker is not possible to
forge the digital signature without
the right private key.
Security Goal 3
Device Attack. fake reader has no
way to get authenticated, because
it cannot get a valid private key.
Security Goal 4
Internal Attack. The authentication
request from a lost legitimate
reader can be blocked, because the
reader cannot provide the right
task information.
Security Goal 5
16

17. Algorithm 1
Eavesdropping. all communications
are encrypted to prevent
eavesdropping.
Security Goal 1
Brute-Force Attack. using modern
cryptographic algorithms like AES,
the basic brute-force attacks have
been proved to be blocked by using
appropriately sized keys like 256-bit
keys.
Security Goal 2
Man-in-the-Middle Attack. an
MITM attacker is not possible to
forge the digital signature without
the right private key.
Security Goal 3
Device Attack. fake reader has no
way to get authenticated, because
it cannot get a valid private key.
Security Goal 4
Internal Attack. The authentication
request from a lost legitimate
reader can be blocked, because the
reader cannot provide the right
task information.
Security Goal 5
Replay Attack. attack can be mostly
disabled by the use of one-time shared
key in the reader-device authentication.
In addition, use timestamps to prevent
reply attack.
Security Goal 6
17

18. Algorithm 1
18

19. Algorithm 1
Eavesdropping. all communications
are encrypted to prevent
eavesdropping.
Security Goal 1
Man-in-the-Middle Attack. In the
reader-device authentication, a
symmetric key is shared between
the reader and the smart device.
Anyone who does not have the key
cannot win the trust from either
the reader or the smart grid device.
Security Goal 3
19

20. Algorithm 1
Eavesdropping. all communications
are encrypted to prevent
eavesdropping.
Security Goal 1
Man-in-the-Middle Attack. In the
reader-device authentication, a
symmetric key is shared between
the reader and the smart device.
Anyone who does not have the key
cannot win the trust from either
the reader or the smart grid device.
Security Goal 3
Forward Secrecy. the compromise
of one shared key will not cause the
compromise of others without
knowing three other parameters
used in new key generation.
Security Goal 7
20

21. Algorithm 1
Eavesdropping. all communications
are encrypted to prevent
eavesdropping.
Security Goal 1
Man-in-the-Middle Attack. In the
reader-device authentication, a
symmetric key is shared between
the reader and the smart device.
Anyone who does not have the key
cannot win the trust from either
the reader or the smart grid device.
Security Goal 3
Forward Secrecy. the compromise
of one shared key will not cause the
compromise of others without
knowing three other parameters
used in new key generation.
Security Goal 7
DoS Attack. all rounds of message exchange between the reader
and the device are encrypted using a key shared between them,
and any message without this encryption can be neglected.
Security Goal 8
21

22. •Network Model
Algorithm 2 [2]
22
[2] Chen, Yuwen, José-Fernán Martínez, Pedro Castillejo, and Lourdes López. "A bilinear map pairing based authentication scheme for smart grid communications: Pauth." IEEE Access 7
(2019): 22633-22643.

23. Algorithm 2
•Security Goals
1. Work against replay attack
2. Message integrity
3. Private key privacy
4. Perfect forward privacy
5. Early detection of illegal message
23

24. •Registration process
Algorithm 2
24

25. •Registration process
Algorithm 2
The proposed registration scheme
is secure against an external
adversary under the assumption
of ECDL problem
Elliptic Curve Discrete Logarithm (ECDL)
problem. Suppose 𝐺1 is a cyclic additive
group of prime order 𝑞, 𝑃 is a generator
of 𝐺1. Given an element 𝑄 Of 𝐺1, it is
computationally intractable to find a 𝑐 ∈
𝑍𝑞
∗
such that 𝑄 = 𝑐𝑃.
Complexity
25

26. •Authentication process.
Algorithm 2
26

27. •Authentication process.
Algorithm 2
The proposed scheme achieves
mutual authentication under the
assumption of the ECCDH
problem
the Elliptic Curve Computational
Diffie-Hellman (ECCDH) problem.
Suppose 𝐺1 is a cyclic additive group
of prime order 𝑞, 𝑃 is a generator of
𝐺1. For any 𝑎, 𝑏, 𝑐 ∈ 𝑍𝑞
∗
, given an
instance < 𝑎𝑃, 𝑏𝑃 > , it is
computationally intractable to
compute 𝑐𝑃 = 𝑎𝑏𝑃.
Complexity
Point in a group
Point in a group
27

28. •Authentication process.
Algorithm 2
28

29. •Authentication process.
Algorithm 2
The proposed scheme achieves
perfect forward privacy under
the assumption of the BCDH
problem
Bilinear Computational Diffie-
Hellman (BCDH) problem. Suppose
𝐺1 is a cyclic additive group of
prime order 𝑞, 𝑃 is a generator of
𝐺1. For any 𝑎, 𝑏, 𝑐 ∈ 𝑍𝑞
∗
, given an
instance < 𝑎𝑃, 𝑏𝑃, 𝑐𝑃 > , it is
computationally intractable to
compute 𝑒 𝑃, 𝑃 𝑎𝑏𝑐
.
Complexity
29

30. •Authentication process.
Algorithm 2
30

31. •Authentication process.
Algorithm 2
REPLAY ATTACK. in the scheme
there is a timestamp 𝑇1 in the
message
Security Goal 1
31

32. •Authentication process.
Algorithm 2
REPLAY ATTACK. in the scheme
there is a timestamp 𝑇1 in the
message
Security Goal 1
MESSAGE INTEGRITY. the
signature in message ensure the
integrity of the message
Security Goal 2
32

33. •Authentication process.
Algorithm 2
𝑑𝑖 = 𝑒𝑖 ∙ 𝑘𝑛 + 𝑘𝑢 + 𝑑𝑥
REPLAY ATTACK. in the scheme
there is a timestamp 𝑇1 in the
message
Security Goal 1
MESSAGE INTEGRITY. the
signature in message ensure the
integrity of the message
Security Goal 2
PRIVATE KEY PRIVACY. the private key
of an entity is 𝑑𝑖 the network
manager knows 𝑑𝑥 , 𝑒𝑖 and 𝑘𝑛 ,
however, it does not know 𝑘𝑢, it is
unable to know the private key of an
arbitrary entity
Security Goal 3
33

34. •Authentication process.
Algorithm 2
REPLAY ATTACK. in the scheme
there is a timestamp 𝑇1 in the
message
Security Goal 1
MESSAGE INTEGRITY. the
signature in message ensure the
integrity of the message
Security Goal 2
PRIVATE KEY PRIVACY. the private key
of an entity is 𝑑𝑖 the network
manager knows 𝑑𝑥 , 𝑒𝑖 and 𝑘𝑛 ,
however, it does not know 𝑘𝑢, it is
unable to know the private key of an
arbitrary entity
Security Goal 3
PERFECT FORWARD PRIVACY. For the
scheme, even if the private keys of both
entities are leaked, the adversary is
unable to get the shared key of the past
sessions.
Security Goal 4
34

35. •Authentication process.
Algorithm 2
REPLAY ATTACK. in the scheme
there is a timestamp 𝑇1 in the
message
Security Goal 1
MESSAGE INTEGRITY. the
signature in message ensure the
integrity of the message
Security Goal 2
PRIVATE KEY PRIVACY. the private key
of an entity is 𝑑𝑖 the network
manager knows 𝑑𝑥 , 𝑒𝑖 and 𝑘𝑛 ,
however, it does not know 𝑘𝑢, it is
unable to know the private key of an
arbitrary entity
Security Goal 3
PERFECT FORWARD PRIVACY. For the
scheme, even if the private keys of both
entities are leaked, the adversary is
unable to get the shared key of the past
sessions.
Security Goal 4
EARLY DETECTION OF ILLEGAL
MESSAGE. For the proposed scheme, if
an adversary sends a fake message to
entity 𝑉
𝑗. 𝑉
𝑗 can find out this message is
not a legitimate one by checking the
timestamp and the signature
Security Goal 5
35

36. Algorithm 3 [3]
•Network Model
[3] Wazid, Mohammad, Ashok Kumar Das, Neeraj Kumar, and Joel JPC Rodrigues. "Secure three-factor user authentication scheme for renewable-energy-based smart grid environment." IEEE
Transactions on Industrial Informatics 13, no. 6 (2017): 3144-3153. 36

37. Algorithm 3
•Security Goals
1. Man-in-the-Middle Attack
2. Smart Meter Impersonation Attack
3. User Impersonation Attack
4. Privileged-Insider Attack
5. Password Change Attack
6. Replay Attack
7. Ephemeral Secret Leakage (ESL) Attack
8. Anonymity and Untraceability
37

38. Algorithm 3
𝑅𝐼𝐷𝑖 = ℎ(𝐼𝐷𝑖 ∥ 𝑘)
𝑅𝐼𝐷𝑆𝑀 = ℎ(𝐼𝐷𝑆𝑀 ∥ 𝑘)
Registration on mobile device
Password & Biometric
1 1
2
3
4
Login
Authentication
𝑅𝐼𝐷𝑇𝐴 = ℎ(𝐼𝐷𝑇𝐴 ∥ 𝑘)
& 𝑅𝐼𝐷𝑇𝐴 & 𝑅𝐼𝐷𝑇𝐴
38

39. Algorithm 3
𝑅𝐼𝐷𝑖 = ℎ(𝐼𝐷𝑖 ∥ 𝑘)
𝑅𝐼𝐷𝑆𝑀 = ℎ(𝐼𝐷𝑆𝑀 ∥ 𝑘)
Registration on mobile device
Password & Biometric
1 1
2
3
4
Login
Authentication
Man-in-the-Middle Attack. it is not
possible to fool both sides if the
attacker does not know secret
credentials RIDi, RIDSM and RIDTA.
Security Goal 1
Smart Meter Impersonation
Attack. Without having the secret
credentials RIDSM and RIDTA, the
attacker cannot impersonate the
smart meter.
Security Goal 2
𝑅𝐼𝐷𝑇𝐴 = ℎ(𝐼𝐷𝑇𝐴 ∥ 𝑘)
& 𝑅𝐼𝐷𝑇𝐴 & 𝑅𝐼𝐷𝑇𝐴
User Impersonation Attack.
Without having the secret
credentials RIDi and RIDTA, also,
the Password & Biometric. The
attacker cannot impersonate the
user.
Security Goal 3
Privileged-Insider Attack. if the
attacker is insider user and can get
the registration information,
Without having the biometric key
and the password, he cannot use
the mobile device.
Security Goal 4
Password Change Attack. To
change the password to another
password the attacker require
to input the correct ID and the
old password and the biometric
of the user.
Security Goal 5
Suppose an adversary
has stolen mobile device
of a registered user.
39

40. Algorithm 3
40

41. Algorithm 3
Replay Attack. all these messages
include the timestamps T1, T2, and
T3, validity of the timestamps will
fail.
Security Goal 6
Ephemeral Secret Leakage (ESL)
Attack. The attacker should know
the secrets rui and rsj, also, the RIDI,
RIDSM and RIDTA to calculate the
secret shared key
Security Goal 7
Anonymity and Untraceability. Due
to usage of the random, current
timestamps and the collision-
resistant on-way hash function, the
messages exchanged during the
login, and authentication and key
agreement phases are different for
each session.
Security Goal 8
41

42. Security Comparison
Security Feature [1] [2] [3]
Eavesdropping X X ✓
Replay attack ✓ ✓ ✓
Private key privacy ✓ ✓ ✓
Perfect forward privacy X ✓ ✓
Early detection of illegal entities X ✓ X
Message integrity X ✓ X
Man-in-the-Middle ✓ X ✓
Impersonation ✓ ✓ ✓
Internal Attack ✓ X ✓
Ephemeral Secret Leakage ✓ X X
Brute-Force X X X
Denial-of-Service X X ✓
Anonymity and Untraceability ✓ X X
Password Change ✓ X X
42

43. Authentication Schemes Summary
Authentication
ID Based
Hash function
[1]
Bilinear
pairing [2]
Encryption [3]
43

44. 44
Thank You
Any Questions?