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Modulo 15: Cryptografics Services - Coggle Diagram
Modulo 15: Cryptografics Services
15.1 Secure Communications
15.1.1 Authentication, Integrity, and Confidentiality
There are three primary objectives of securing communications:
Integrity -
This guarantees that no one intercepted the message and altered it; similar to a checksum function in a frame. This is provided by implementing the SHA-2 or SHA-3 family of hash-generating algorithms.
Confidentiality -
This guarantees that if the message is captured, it cannot be deciphered. This is provided using symmetric or asymmetric encryption algorithms.
Authentication -
This guarantees that the message is not a forgery and actually comes from the authentic source. Modern networks ensure authentication using hash message authentication code (HMAC).
15.1.2 Authentication
Entering an ATM Authentication PIN
Data nonrepudiation is a similar service that allows the sender of a message to be uniquely identified. With nonrepudiation services in place, a sender cannot deny having been the source of that message.
15.1.3 Data Integrity
Data integrity ensures that messages are not altered in transit. With data integrity, the receiver can verify that the received message is identical to the sent message and that no manipulation occurred.
Wax Seal Ensuring Integrity
15.1.4 Data Confidentiality
Data confidentiality ensures privacy so that only the receiver can read the message. This can be achieved through encryption. Encryption is the process of scrambling data so that it cannot be easily read by unauthorized parties.
Encoded Caesar Cipher Message
15.2 Cryptography
15.2.1 Creating Cipher Text
Stycale
ceaser cipher
vigenere cipher
Enigma Machine
15.2.2 Transposition Ciphers
plaintext message
Encryption Procces
Encrypted message
15.2.3 Substitution Ciphers
plaintext message
Encrypted message
Encryption Procces
15.2.4 A More Complex Substitution Cipher
15.2.5 One-Time Pad Ciphers
Example of One-Time Pad Device
15.3.1 Cracking Code
Throughout history, there have been many instances of cryptanalysis:
The Vigenère cipher had been absolutely secure until it was broken in the 19th century by English cryptographer Charles Babbage.
Mary, Queen of Scots, was plotting to overthrow Queen Elizabeth I from the throne and sent encrypted messages to her co-conspirators. The cracking of the code used in this plot led to the beheading of Mary in 1587.
The Enigma-encrypted communications were used by the Germans to navigate and direct their U-boats in the Atlantic. Polish and British cryptanalysts broke the German Enigma code. Winston Churchill was of the opinion that it was a turning point in WWII.
15.3.2 Methods of Cracking Code
Several methods are used in cryptanalysis:
Brute-force method - The attacker tries every possible key knowing that eventually one of them will work.
Ciphertext method - The attacker has the ciphertext of several encrypted messages but no knowledge of the underlying plaintext.
Known-Plaintext method - The attacker has access to the ciphertext of several messages and knows something about the plaintext underlying that ciphertext.
Chosen-Plaintext method - The attacker chooses which data the encryption device encrypts and observes the ciphertext output.
Chosen-Ciphertext method - The attacker can choose different ciphertext to be decrypted and has access to the decrypted plaintext.
Meet-in-the-Middle method - The attacker knows a portion of the plaintext and the corresponding ciphertext.
15.3.3 Cracking Code Example
15.4 Cryptology
15.4.1 Making and Breaking Secret Codes
Cryptology = Cryptography + Cryptanalysis
15.4.2 Cryptanalysts
Cryptanalysis is often used by governments in military and diplomatic surveillance, by enterprises in testing the strength of security procedures, and by malicious hackers in exploiting weaknesses in websites.
15.4.3 The Secret is in the Keys
In the world of communications and networking, authentication, integrity, and data confidentiality are implemented in many ways using various protocols and algorithms.
