Cryptanalysis 101
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Cryptanalysis is the study of encrypted messages to understand encryption systems and find weaknesses. Cryptanalysts aim to decrypt messages without knowing the encryption key or algorithm. Their research helps cryptographers strengthen algorithms. Cryptanalysts uncover design flaws that can reduce the number of keys tested on a message. Their work is used by governments and companies to test security products.
Cryptanalysis 101
- 1. CRYPTANALYSIS Cryptanalysis is the study of ciphertext, ciphers and cryptosystems with the aim of understanding how they work and finding and improving techniques for defeating or weakening them.
- 2. INTRODUCTION cryptanalysts seek to decrypt ciphertexts without knowledge of the plaintext source, encryption key or the algorithm used to encrypt it
- 3. GOAL cryptanalysts' research results are used by cryptographers to improve and strengthen or replace flawed algorithms
- 4. CONT…………. cryptanalytic results uncover weaknesses in the design or implementation of the algorithm, which can reduce the number of keys that need to be tried on the target ciphertext
- 7. cryptanalysis is practiced by a broad range of organizations Including ▣ governments aiming to decipher other nations' confidential communications ▣ companies developing security products that employ cryptanalysts to test their security features etc.
- 11. The attacker only has access to one or more encrypted messages but knows nothing about the plaintext data ▣ the encryption algorithm being used ▣ any data about the cryptographic key being used This is the type of challenge that intelligence agencies often face when they have intercepted encrypted communications from an opponent
- 13. The analyst may have access to some or all of the plaintext of the ciphertext. The analyst's goal in this case is to discover the key used to encrypt the message and decrypt the message. Once the key is discovered, an attacker can decrypt all messages that had been encrypted using that key.
- 15. chosen plaintext attack The analyst either knows the encryption algorithm or has access to the device used to do the encryption. The analyst can encrypt the chosen plaintext with the targeted algorithm to derive information about the key
- 17. Dictionary attack ▣ a technique typically used against password files and exploits the human tendency to use passwords based on natural words or easily guessed sequences of letters or numbers
- 19. Man-in-the-middle attacks ▣ occur when cryptanalysts find ways to insert themselves into the communication channel between two parties who wish to exchange their keys for secure communication via asymmetric or public key infrastructure The attacker then performs a key exchange with each party, with the original parties believing they are exchanging keys with each other. The two parties then end up using keys that are known to the attacker.
- 21. Brute Force Attack ▣ A brute force attack is any type of attack that involves trying every possible combination of characters or data in order to find the key in order to decrypt an encrypted message. ▣ A brute force attack is usually used as a last-resort tactic in a cryptanalysis scenario, as it very much involves extreme amounts of trial and error and relies on a lot of luck in order to find the key. A brute force attack is different from a dictionary attack, as it does not rely on a dictionary and simply tries every possible key that could be used.