With vast networks and requirements of global communications, it is practically not feasible to have only one trusted CA from whom all users obtain their certificates. Secondly, availability of only one CA may lead to difficulties if CA is compromised. In such case, the hierarchical certification model is of interest since it allows public key… Continue reading Hierarchy of CA
Month: November 2022
Certifying Authority (CA)
As discussed above, the CA issues certificate to a client and assist other users to verify the certificate. The CA takes responsibility for identifying correctly the identity of the client asking for a certificate to be issued, and ensures that the information contained within the certificate is correct and digitally signs it. Key Functions of… Continue reading Certifying Authority (CA)
Public Key Infrastructure (PKI)
PKI provides assurance of public key. It provides the identification of public keys and their distribution. An anatomy of PKI comprises of the following components. Digital Certificate For analogy, a certificate can be considered as the ID card issued to the person. People use ID cards such as a driver’s license, passport to prove their… Continue reading Public Key Infrastructure (PKI)
Public Key Infrastructure
The most distinct feature of Public Key Infrastructure (PKI) is that it uses a pair of keys to achieve the underlying security service. The key pair comprises of private key and public key. Since the public keys are in open domain, they are likely to be abused. It is, thus, necessary to establish and maintain… Continue reading Public Key Infrastructure
Importance of Digital Signature
Out of all cryptographic primitives, the digital signature using public key cryptography is considered as very important and useful tool to achieve information security. Apart from ability to provide non-repudiation of message, the digital signature also provides message authentication and data integrity. Let us briefly see how this is achieved by the digital signature −… Continue reading Importance of Digital Signature
Cryptography Digital signatures
Digital signatures are the public-key primitives of message authentication. In the physical world, it is common to use handwritten signatures on handwritten or typed messages. They are used to bind signatory to the message. Similarly, a digital signature is a technique that binds a person/entity to the digital data. This binding can be independently verified… Continue reading Cryptography Digital signatures
Message Authentication
In the last chapter, we discussed the data integrity threats and the use of hashing technique to detect if any modification attacks have taken place on the data. Another type of threat that exist for data is the lack of message authentication. In this threat, the user is not sure about the originator of the message.… Continue reading Message Authentication
Whirlpool
This is a 512-bit hash function. Applications of Hash Functions There are two direct applications of hash function based on its cryptographic properties. Password Storage Hash functions provide protection to password storage. Data Integrity Check Data integrity check is a most common application of the hash functions. It is used to generate the checksums on… Continue reading Whirlpool
Popular Hash Functions
Let us briefly see some popular hash functions − Message Digest (MD) MD5 was most popular and widely used hash function for quite some years. Secure Hash Function (SHA) Family of SHA comprise of four SHA algorithms; SHA-0, SHA-1, SHA-2, and SHA-3. Though from same family, there are structurally different. RIPEMD The RIPEMD is an… Continue reading Popular Hash Functions
Properties of Hash Functions
In order to be an effective cryptographic tool, the hash function is desired to possess following properties − Design of Hashing Algorithms At the heart of a hashing is a mathematical function that operates on two fixed-size blocks of data to create a hash code. This hash function forms the part of the hashing algorithm.… Continue reading Properties of Hash Functions