Concealment Ciphers vs. Running Key Ciphers
Both of these ciphers types are early or classical methods for producing cipher-text. Concealment ciphers work by concealing or hiding the plain-text message within another message.
Running-key ciphers rely on a simple square table of alphabets called a "tabula recta" and a chunk of text from a previously agreed-upon source called a "polyalphabetic source". The tabula recta is a table made up of rows of the alphabet, with each row computed by shifting the preceding letter to the left. The plain-text is substituted with chunks of text from the polyalphabetic source, and the cipher-text is then derived by the value in tabula recta. The "key" here is the polyalphabetic source. Table below shows a truncated tabula recta.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A A B C D E F G H I J K L M N O P Q R S T U V W X Y Z B B C D E F G H I J K L M N O P Q R S T U V W X Y Z A C C D E F G H I J K L M N O P Q R S T U V W X Y Z A B D D E F G H I J K L M N O P Q R S T U V W X Y Z A B c
Substitution Ciphers vs. Transposition Ciphers
Substitution ciphers work by replacing/substituting parts or the whole of the plain-text with something else. A key is used to predetermine how the substitution should take place.
Transposition ciphers, on the other hand, do not rely on substitution; instead, parts of the plain-text are moved or juggled around to hide the meaning of the original plaintext.
In this tutorial:
- Securing Wireless Networks
- Security Background
- Security Services
- Cryptographic Concepts and Terms
- Encryption and Decryption
- Exclusive OR (XOR)
- Asymmetric Encryption Algorithms
- Public-Private Key Cryptography
- Concealment Ciphers vs. Running Key Ciphers
- Stream Ciphers vs. Block Ciphers
- Cipher Examples
- Cipher Implementations
- Wi-Fi Protected Access
- Wi-Fi Protected Access 2 (WPA2)
- Hash Functions
- EAP Entities
- EAP Grammar
- EAP Types
- IEEE 802.11i
- Four-Way Handshake
- IEEE 802.11i Considerations