Métodos de criptoanálisis clásico

• Primera aprobación por la NSA de un número para uso público con materiales clasificados como TOP SECRET para el uso de criptografía asimétrica.
• Diffie-Hellman (1976) protocol, a desarrollado por Whitfield Diffie y Martin Hellman, is a protocol for establishing keys between parties without prior contact, using an insecure and anonymous channel.
• Criptografía asimétrica, also known as public-key cryptography or two-key cryptography, is a cryptographic system that uses two keys, a public key and a private key, for sending messages or computer data.
• Principio de Kerckhoffs: All security should rest on the key, not on the algorithm. The size of the key is a measure of the system's security, but the comparison of the key size between symmetric and asymmetric encryption is not possible.
• RSA (Rivest, Shamir, y Adleman): A public-key cryptographic system developed in 1979 that uses integer factorization. It is the first and most widely used of its type and is valid for encryption as well as digital signing.
• RSA security relies on the difficulty of integer factorization. Messages are represented as numbers, and the process is based on the product, known, of two large prime numbers kept secret.
• For signing (authenticity, integrity, and non-repudiation), the sender generates a hash of the message to sign, processes it with their private key, and sends both the message and the signature. The receiver recalculates the hash and decrypts the hash with the sender's public key to validate the signature.
• Functions Hash: Values represent information in a concise, fixed-length format. They can be applied to inputs of any size. Examples include the MD family, the official USO SHA, and RIPEMD-160.
• Uses of hash functions: USO OFICIAL. Hash functions are used to compare symmetric and asymmetric encryption. They protect the integrity and authenticity of data.
• Criptoanálisis: Study branch of cryptography that explores ways to break codes and cryptosystems. Cryptoanalysis develops techniques for the more efficient breaching of encrypted data. The oldest recorded explanation of cryptography was given in the 9th century by the mathematician Abu Yusuf Yaqub ibn Ishaq al-Sabbah Al-Kindi in a manuscript called "About Deciphering Encrypted Messages."
• Cryptoanalysis methods: Ciphertext-only: The analyst only has access to a limited collection of ciphertexts. Known-plaintext: The attacker has a set of plaintexts and their corresponding ciphertexts.
• Cryptoanalysis techniques: Analytical methods that break encryption methods by determining the key used based on the text encrypted. Modern techniques also exploit weaknesses in the system.
• History of cryptoanalysis: The earliest written explanation of cryptography was given in the 9th century by the mathematician Abu Yusuf Yaqub ibn Ishaq al-Sabbah Al-Kindi in a manuscript called "Sobre el descifrado de mensajes criptográficos." This treatise includes a description of the frequency analysis method.
• Cryptoanalysis goal: A cryptographic method is broken when it is possible to determine the key used based on the encrypted text. Modern analytical methods also rely on exploiting weaknesses in the system.

Identifica los métodos de criptoanálisis clásico que no ocultan las propiedades del mensaje en claro, solo las dispersan, y aprende sobre permutaciones de filas y columnas para mejorar el tamaño del espacio de claves. Descubre también cómo reconstruir la clave utilizando las frecuencias de aparición de los diagramas.