Learn Cryptography in Just 3 Hrs: Encryption, Hashing, SSL/TLS, PKI, Public-Private Key, Digital Signature

Rashmi Shah

Oct 2022 · HadoopExam Learning Resources

About this ebook

Cryptography, SSL/TLS, HTTPS, Public Key, Private Key, Digital certificates, PKI (Public Key Infrastructure is a very confusing subject and ideally if you are a developer you need to know basics of its workings and this book is covering that. You don’t need to hours to understand this concept this is the book we have created for you and make sure that your fundamental understanding of SSL/TLS certificate, public-private key, PKI, Cryptography, Digital certificate all are covered in just few hours and you should not spend many days to understand the same. In fact, to validate your understanding this book cover 45+ interview questions. If you see all the big publisher publishes books with 300 and 400 pages which requires many days to complete a single book and most of the reader reads first 2-3 chapters of the book and leave it for many days and they start again from first chapter. We don’t want you to face the similar problem, just read this book in one sitting and also give you fundamental learning in just couple of hours and spend another hour for question and answer-based learning. Anytime, you want to revise this concepts comeback to book finish the same in couple of hours.

Cryptography is the study of secure communications techniques that allow only the sender and intended recipient of a message to view its contents. The term is derived from the Greek word kryptos, which means hidden. It is closely associated to encryption, which is the act of scrambling ordinary text into what's known as ciphertext and then back again upon arrival. In addition, cryptography also covers the obfuscation of information in images using techniques such as microdots or merging. Ancient Egyptians were known to use these methods in complex hieroglyphics, and Roman Emperor Julius Caesar is credited with using one of the first modern ciphers.

When transmitting electronic data, the most common use of cryptography is to encrypt and decrypt email and other plain-text messages. The simplest method uses the symmetric or "secret key" system. Here, data is encrypted using a secret key, and then both the encoded message and secret key are sent to the recipient for decryption. The problem? If the message is intercepted, a third party has everything they need to decrypt and read the message. To address this issue, cryptologists devised the asymmetric or "public key" system. In this case, every user has two keys: one public and one private. Senders request the public key of their intended recipient, encrypt the message and send it along. When the message arrives, only the recipient's private key will decode it — meaning theft is of no use without the corresponding private key.