Mono alphabetic and poly alphabetic substitution techniques Vigenere Cipher

In this video, we will discuss two important techniques in cryptography: monoalphabetic and polyalphabetic substitution ciphers. We will also discuss the Vigenere cipher, which is a type of polyalphabetic substitution cipher. Monoalphabetic substitution ciphers In a monoalphabetic substitution cipher, each plaintext letter is always substituted by the same ciphertext letter. For example, in a Caesar cipher, each letter is shifted three positions down the alphabet. Monoalphabetic substitution ciphers are relatively easy to break because the frequency distribution of the letters in the ciphertext is the same as the frequency distribution of the letters in the plaintext. This means that an attacker can use frequency analysis to guess the ciphertext letters. Polyalphabetic substitution ciphers In a polyalphabetic substitution cipher, each plaintext letter is substituted by a different ciphertext letter, depending on the position of the letter in the plaintext. This makes it much more difficult to break the cipher using frequency analysis. The Vigenere cipher is a type of polyalphabetic substitution cipher that uses a keyword to determine the ciphertext letters. The keyword is repeated over and over again, and each letter of the plaintext is substituted by the letter of the ciphertext that corresponds to the current position of the keyword. The Vigenere cipher is a more secure cipher than a monoalphabetic substitution cipher, but it is still vulnerable to certain attacks. For example, if an attacker knows the keyword, then they can break the cipher. Conclusion Monoalphabetic and polyalphabetic substitution ciphers are two important techniques in cryptography. The Vigenere cipher is a type of polyalphabetic substitution cipher that is more secure than a monoalphabetic substitution cipher, but it is still vulnerable to certain attacks. 👉 Download Ekeeda Application & Learn from the best professors with 10+ years of experience. Subscribe to a Course or Start a Free Trial of Package. ✤ Download the Ekeeda - Learning App for Engineering Courses App here: ➤ Android & iOS: https://ekeeda.com/download.html Access the Complete Playlist of Subject GATE Algorithms - https://www.youtube.com/playlist?list=PLO4TWepMw7ggN22wYVdfE7KmOcMjNHh4m ✤ For More Such Classes Get Subscription Advantage: 👉 GATE Algorithms (GATE Computer Science and Information Technology): https://ekeeda.com/gate/gate-computer-science-and-information-technology/algorithms 👉 GATE Computer Science and Information Technology: https://ekeeda.com/gate/gate-computer-science-and-information-technology 👉 Explore our Courses - https://ekeeda.com/catalog Like us on Facebook: https://www.facebook.com/Ekeeda Follow us on Instagram: https://www.instagram.com/ekeeda_official/ Follow us on Twitter: https://twitter.com/ekeeda_official Follow us on LinkedIn: https://www.linkedin.com/company/ekeeda.com Visit Our Website: https://ekeeda.com/ Subscribe to Ekeeda Channel to access more videos: https://www.youtube.com/c/Ekeeda?sub_confirmation=1