SLCrypt

Description:

Class for encrypting and decrypting text using a key and an initialization vector.
The size of the key and the initialization vector is equal blockBytesLen, by default it is 128 bits.
You can set the length of block manually using setBlockSize method. (the length is in bits)

How does it work (ECB):

• Encryption:

  • We split the string into blocks, each 16 bytes
  • Generate an initialization vector (random letters, 128 bits)
  • For each byte of the string, we increment the byte
    of the initialization vector and decrement the byte of the key
  • Add an initialization vector to the beginning of the string

• Decryption:

  • Split string and initialization vector (first 128 bits)
  • We split the string into blocks, each 16 bytes
  • For each byte of string, we decrement the byte
    of the initialization vector and increment the byte of the key