International Journal of Information Management 38 (2018) 42–44
Contents lists available at ScienceDirect
International Journal of Information Management
journal homepage: www.elsevier.com/locate/ijinfomgt
Case study
Analyze encryption and public key infrastructure (PKI)
Vincent Lozupone
MARK
Northcentral University, 2488 Historic Decatur Rd., San Diego, CA, 92106, United States
A R T I C L E I N F O
A B S T R A C T
Keywords:
Symmetric encryption
Secret key
Private key
Cryptography
Digital signatures
Hash functions
Lockbox
Block ciphers
The researcher opens with a brief description of symmetric and asymmetric encryption systems. Then the researcher presents an analysis, comparisons of asymmetric and symmetric encryption schemes and advantages
and disadvantages of PKI (Public Key Infrastructure). Asymmetric encryption systems use different transmitter
and receiver keys, and it is very difficult to derive one key from the other. Symmetric systems use one shared key.
PKI is a set of hardware, software, policies, and technicians to manage an environment using public key digital
certificates. The researcher addresses security, PKI, and solutions within cloud technology.
1. Introduction
Symmetric encryption is the oldest and well-known technique. It
uses a secret key that can be a number, word, or random letters. All the
parties, the sender, and receiver need to have the key in their possession. There is a problem with the concept of a secret key. Having the
knowledge of this secret key can decrypt the message. The solution to
this issue is to use a key-pair. Use a public key, that anyone can hold,
and a private key. A PKI system allows both encryption and digital
signatures by a wide breadth and diverse set of applications (Entrust,
2017).
2. A critical analysis of similarities and differences between a
symmetric and asymmetric encryption system
Gaining a strong understanding of cryptography requires a grasp of
the four main areas of primitives. All the primitives are very closely
related. The four primitives are random number generation, symmetric
encryption, asymmetric encryption, and hash functions (Cole, 2008).
There are three main goals that cryptographic systems attempt to attain. Confidentiality is one the objectives. If a user can decrypt the
message without having a key, then this objective is not met. To assure
the data has not been modified is the goal of the objective of integrity.
Authentication, the third goal, is to assure that the source of the data is
verified (Cole, 2008). Asymmetric encryption is more secure and more
complex than symmetric encryption (Omar, Asif, Mahaboob,
Ramana, & Shahid, 2012).
Asymmetric encryption uses private and public keys to encrypt and
decrypt information as shown in Fig. 2. Cole (2008) stated that
E-mail address: vlozupone@hotmail.com.
http://dx.doi.org/10.1016/j.ijinfomgt.2017.08.004
Received 22 April 2017; Received in revised form 9 August 2017; Accepted 25 August 2017
0268-4012/ © 2017 Elsevier Ltd. All rights reserved.
symmetric encryption or single key encrypt and decrypt data as illustrated in Fig. 1. A benefit of using a single key encryption is speed.
Coincidently, symmetric key encryption used with asymmetric encryption also makes a fast transaction (Cole, 2008). One would use
symmetric encryption when sending confidential information. It can
also be used to offer integrity. An excellent analogy explaining this type
of encryption is similar to a lockbox (Cole, 2008).
The equivalent to a key is a set of random bits. There are some block
ciphers used for symmetric encryption, but the one that is the most
popular is DES (Data Encryption Standard). It has a key of 56 bits. This
value means that it would take 72, 057, 594, 037, 927, 936 varying
keys to test to full exhaustion (Cole, 2008). Compared to symmetric
encryption, asymmetric encryption needs two keys, a private key, and a
public key. The public key is available to anyone who chooses to use it.
Asymmetric encryption is slower than symmetric encryption because it
uses number theory to increase its strength. Regardless of its slow
speed, it does an excellent job of the difficulty of sharing keys.
Two mechanisms use asymmetric encryption, digital signatures, and
hashes. A digital signature message is one that uses authentication to
prove a certain person sent the message and used to meet important
security goals (Villanueva, 2015). The authentication accomplishes by
only encrypting a smaller section of the entire message, which then
makes the process faster than encrypting the entire message (Cole,
2008). Hash functions are used to gain improved performance when
large blocks of data are using with asymmetric encryption (Cole, 2008).
Hashes have three properties that make them valuable. It is doubtful
that the same messages can hash identically. With a known digest, it
would be nearly impossible for a second message to create the same
digest. Finally, it would also be almost impossible to locate the original
International Journal of Information Management 38 (2018) 42–44
V. Lozupone
can be a public third-party such as Verisign, Thawte or RSA. An organization can also create one for itself. To create a certificate, a PKIenabled application is required. The CR (Certificate Request) contains a
public key and information used to submit the type of certificate requested (Cole, 2008). The organization needs to decide the types of
certificates required, and this would determine whether implementation of a public or private CA. If an organization chooses a private CA,
then a choice has to be made of roles that are a Root CA, Intermediate
CA, or an Issuing CA. It is prudent to design a system with multiple CAs
to assure available and secure distributing points (Cole, 2008).
Another critical component of a PKI implementation is the certificate policy. Uahhab and Bakkali (2014) stated that it lays out the rules
for leading key security, the process for issuing, renewing, revoking,
and default life span of certificates. Private PKI’s should institute precise policies to assure methods of identifying certificate holders, revocation of the certificates, and the methods of list distribution. Revocation is another critical component of PKI.
Upon request, the requestor sends a created pair to the CA. The
signature must verify. The occasions of revocation are compromised
key or an employee dismissal. The key revokes when a new certificate
replaces a previous one, or the CA is decommissioned (Cole, 2008). The
issuing enterprise CA publishes and distributes a list called a CRL
(Certificate Revocation List) (Uahhab & Bakkali, 2014). The clients
check the CLR before accepting a certificate. According to Jayapandian,
Rahman, Radhikadevi, and Koushikaa (2016), businesses share data by
way of cloud technology effectively on a worldwide basis. Organizations use various service models, i.e., Service and a Service (SaaS),
Platform as a Service (PaaS), and Infrastructure as a Service (IaaS) in
one or more of these deployment models (private, public, hybrid, and
community) (Jayapandian et al., 2017). Encryption ensures originality
of data and allows secure duplication and construction by proper encryption and decryption (Jayapandian et al., 2017). Jayapandian et al.
(2017) stated that symmetric key encryption or secret key encryption
prevent information from eavesdroppers.
According to the survey, Information Technology (IT) governance
and security standards have an impact on the increased adoption of
cloud technology (Paquet, 2013). Another study by International Data
Corporation (IDC) reveals that 87.5% of the respondents mentioned
that security is the top issue of cloud adoption (Paquet, 2013).
According to Singh (2017), there are possible points of entry for an
intruder into a cloud technology (a) insecure mobile phone access to
data, (b) a web application with vulnerability, and (c) sharing a password of a cloud database. It is becoming harder to protect data hosted
on cloud platforms. There is no key transmission outside the enterprise
hence the private key is considered a secure tool protecting enterprise
data (Singh, 2017). Considering Small and Medium Businesses (SMBs)
which are lacking the financial and hardware resources to implement a
PKI solution, Singh (2017) emphasized the use of a publicly offered
OAuth standard, which is an open standard for access delegation. Singh
(2017) stated that encryption would not stop attacks, but it does make
them less likely. It is difficult for businesses to allow clients to manage
cloud resources with passwords and various authentication methods
(Singh, 2017). The solution is implementing Single Sign-On (SSO). After
the customer validates, a ticket allows clients access to all permitted
resources (Singh, 2017).
Two solutions for cloud security are PKI and the use of multiple
cloud solutions. Singh’s (2017) solution for cloud security is to assure
that data is safe for internal and external data (suppliers, clients, and
catalogs). Singh (2017) stated that a symmetric key algorithm applies
so the customer has a high level of trust for their critical data and the
personal key not shared. Therefore, this solution is for Public Cloud
security that combines OAuth authentication along with encryption
algorithms (Singh, 2017).
The second solution uses certificate-based authentication along with
public key cryptography infused to the business confidential data applied before placing the data in the cloud (Singh, 2017). PKI requires a
Fig. 1. Symmetric Encryption (Ssl2buy, 2017).
Fig. 2. Asymmetric Encryption (Ssl2buy, 2017).
message that created the known Digest (Cole, 2008). Hashing is also
valuable in storing passwords and hashing ensuring integrity. A message remains the same regardless of the number of times it is computed.
There was a vulnerability in hashing passwords until salting was used to
prevent a dictionary attack. A dictionary attack uses common words in
the dictionary to attempt a breach to discover a password. Salting is
used to insert pseudo-random data into a message before being hashed
(Cole, 2008).
3. An evaluation of the public key infrastructure used by modern
organizations, the entities involved in PKI, and how PKI works
Entrust (2017) explained that PKI is an all-inclusive system that
provides a public-key encryption and the use of digital signatures. PKI
manages keys and certificates. By making use PKI, an organization can
create and manage a dependable and trustworthy networking environment (Entrust, 2017). PKI is commonly synonymous with asymmetric encryption because it is more secure than symmetric encryption
as depicted in Fig. 3. Two keys relate mathematically use a public and
private key, one for encryption and the other for decryption. Everyone
knows the public key, and only the owner knows the private key
(Braun, Volk, Classen, Buchmann, & Mühlhäuser, 2014). The problem
arises if a public key is used by a party that is not the actual owner of
the public key. To avoid this issue, digital certificates verify the owner
is making use of a CA (Certificate Authority) (Braun et al., 2014). A CA
Fig. 3. Public Key Infrastructure (PKI, 2017).
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International Journal of Information Management 38 (2018) 42–44
V. Lozupone
more secure.
company to sign keys, which some companies find hard to use. Companies have found another solution, which is to public key Secure
Sockets Layer (SSL) or later variant Transport Layer Security (TLS)
(Singh, 2017). It is the researcher’s opinion and that of Singh (2017)
that TLS with PKI is a better panacea because it allows cryptographically hardened methods of authentication in environments that
are unsafe.
5. Conclusion
Certificates provide businesses an attractive security model. The
cost is almost nothing to create. It is lucrative if you can convince a
party to purchase a certificate for about $5.00 per year. This proposition is even more lucrative if one can convince business to purchase a
CA and pay a fee for every issued certificate. A CA means trust.
Regarding cryptography, it means that it handles private keys well.
Symmetric Key Algorithms run much faster than Asymmetric Key
Algorithms, i.e. RSA and in addition, the former uses less memory than
for latter. Furthermore, the security facet of Symmetric Key Encryption
is far superior to the Asymmetric Key Encryption. In cloud platforms,
TLS with PKI is a better solution because it allows cryptographically
secured methods of authentication in environments that are unsafe.
4. An analysis of the advantages and disadvantages associated
with PKI
Oppliger (2014) stated that there are advantages and disadvantages
associated with PKI. Some vendors are selling various versions of PKI
solutions. If the vendor goes bankrupt, it is difficult to obtain service in
the future. Fraudulently issued certificates substitute kernel software
with malware that mimics code-signing certificates is another disadvantage (Oppliger, 2014). Another downside is a company breach
that had issued the CA. Companies think that their information is private. Companies that cannot afford the cost or not willing to yield authority to a third party of a public CA would have to invest in an inhouse solution.
Security is a major concern for all companies that transfer digital
information. These transactions that may be confidential, government
or private information need to be protected from falling into corrupt
hands. PKI is probably the best solution for this problem. Considering
the increased use and number of digital transactions by consumers, a
high assurance requires confidence (Oppliger, 2014). PKI enables the
business community to convey to the consumer that their transactions
and privacy is secure and safe not only from the government but the
prying eyes of organizations. A CA like a trusted third party can increase consumer confidence. Another significant advantage is cost.
According to researchers, PKI will decrease costs attenuating the support of labor-intensive transactions. High speed and increased volume
of transactions will reduce the cost per transactions. This would more
than likely increase the business’ market share. PKI also is one of the
best methods of creating an infrastructure that is safe for Internet
transactions and from hackers, theft of information (PI) Personal Information, and virus injection.
It is also important that there may be occasions where PKI is not
necessary, and a secret encryption is sufficient. These may include an
environment where users can meet in private. This may also include a
closed bank system where a manager, single authority knows all the
keys. PKI is usually not required in a single-user environment. Also, PKI
does not replace symmetric encryption but to augment it to make it
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