Abstract: |
Cryptography is a science that deals on the method of converting plaintext into cipher text, usually with the
help of encryption keys and encryption algorithm. Current standard implementation of cryptography is
proved to require high resource in memory which is not suitable to be implemented in low memory
embedded system, thus a lightweight cryptography are required. Vigenere cipher is one of the encryption
algorithms that was easy to implement and comprehand, which can be used to provide confidentiality from
the third party. Vigenere cipher is a polyalphabetic Ceaser cipher, which means it shifting the character in
plaintext to become character of mod of its key character. Even thou Vigenere cipher are a classical cipher
that doing its cipher using character compared to modern cipher that doing its cipher using bits and byte, it
still can be implemented in modern computer by representing its character based on ASCII Table.
Furthermore, because of this, its character can be extended to contain all alphabet and special character in
the ASCII Table, thus allowing it to encrypt every character that can be represented using ASCII Table.
Originally the resilience of Vigenere cipher is based on two factors: (1) the length of its key, and (2) the
randomness of character in its key. Even though increasing the length and the used random character
provide a great resilience, it takes away the fun of using dictionary word to encrypt the plaintext. To
overcome that, this paper, proposing a method of implementing a Pseudorandom Path that change the flow
of mod use by the Vigenere Cipher to encrypt and decrypt either positive mod or negative mod. Usually
Vigenere Cipher use positive mode to encrypt, while negative mod to decrypt, however this paper propose a
method to combine both mod during encryption or decryption with the supervision from the Pseudorandom
Path. This method of implementation and its result were discussed in this paper and named as Shalala
Cryptography. The results were compared between using original resilience and a Shalala Cryptography
method. The resource requirement to implement this algorithm using C++ language is also shown, which
shows a lightweight cryptography scheme in term of RAM consumption and fast processed time, which are
suitable to be used in WSN or IoT environment. |