Published in IET Software
Received on 6th September 2012
Revised on 24th June 2013
Accepted on 24th July 2013
doi: 10.1049/iet-sen.2012.0137
ISSN 1751-8806
Power evaluation methods for data encryption
algorithms
Tingyuan Nie
1
, Lijian Zhou
1
, Zhe-Ming Lu
2
1
Communication & Electronic Engineering Institute, Qingdao Technological University, No. 11, Fushun Road,
Qingdao, People’s Republic of China
2
School of Aeronautics and Astronautics, Zhejiang University, Zheda Road 38, Hangzhou 310027,
People’s Republic of China
E-mail: tynie@qtech.edu.cn
Abstract: With the increasingly extensive application of networking technology, security of network becomes significant than
ever before. Encryption algorithm plays a key role in construction of a secure network system. However, the encryption
algorithm implemented on resource-constrained device is difficult to achieve ideal performance. The issue of power
consumption becomes essential to performance of data encryption algorithm. Many methods are proposed to evaluate the
power consumption of encryption algorithms yet the authors do not ensure which one is effective. In this study, they give a
comprehensive review for the methods of power evaluation. They then design a series of experiments to evaluate the
effectiveness of three main types of methods by implementing several traditional symmetric encryption algorithms on a
workstation. The experimental results show that external measurement and software profiling are more accurate than that of
uninterruptible power system battery. The improvement of power consumption is 27.44 and 33.53% which implies the
method of external measurement and software profiling is more effective in power consumption evaluation.
1 Introduction
Owing to the rapid development of network in the past
decades, a world filled with ‘ubiquitous’ computational
resources has become reality. Information exchange via
network has become increasingly popular. Network
transmits data via digital signals, which makes them
vulnerable to eavesdropping and unauthorised access. The
ability to encrypt messages before transmission is of
fundamental importance for the security of ubiquitous
computing systems. Therefore, search for the best solution
to offer the necessary protection against frauds or
infringements from the third party is becoming one of the
most essential subjects in security system. A large amount
of encryption techniques were developed to comply with
specific security requirements of information applications.
Generally, most encryption algorithms can be categorised
in several ways: by bl ock size encryption algorithm
operates on, there are block encryption algorithm and
stream encryption algorithm. The block encryption
algorithm encrypts plaintext in chunks of a certain fixed
block size like 64× bits, while the stream encryption
algorithm encrypts plaintext sequentially by one byte or one
bit at a time [1].
By whether key is used for both encryption and decryption,
there are symmetric-key algorithm and asymmetric-key
algorithm. Symmetric-key algorithm uses the same key for
both data encryption and data decryption. The key in
symmetric-key algorithm plays a very important role and it
must be distributed before data transmission. The strength
of symmetric-key algorithm highly depends on the size of
the key. Encryption using longer key is harder to be broken
and yet needs mass computation. The classical
symmetric-key algorithm includes RC2, DES, 3DES,
CAST, RC6, Blowfish and advanced encryption standard
(AES) [2–4]. Asymmetric-key algorithm solves the problem
of key distribution. It uses two different keys at once, a
public key and a private key. Public key is used for data
encryption and known to the public, whereas private key is
used for data decryption and known only to the message
recipient. The classical asymmetric-key algorithm includes
RSA, Elgamal and ECC [5]. The primary advantage of
asymmetric-key algorithm is its high security and
convenience. The private key never needs to be transmitted
or revealed to anyone else. However, the asymmetric-key
algorithm is computationally intensive because of its
mathematical functions.
The execution of encryption algorithm consumes both time
and power when it utilises computer resources. Applying
stronger encryption algorithm on electronic device with
battery may consume more power and drain battery faster.
Hence, constantly using cryptographically strong algorithm
may severely reduce lifetime of battery-powered devices
such as cellular phone, PDA etc. Users and designers need
to be aware of both benefits and costs for using encryption
algorithm. The correct way to design a power-effective
security protocol requires a comprehensive understanding
for the power consumption of encryption schemes. The
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The Institution of Engineering and Technology 2014
IET Softw., 2014, Vol. 8, Iss. 1, pp. 12–18
doi: 10.1049/iet-sen.2012.0137