MineCipher

I built a simple MineSweeper inspired Cipher which makes use of the inherent elements of Minesweeper.

The Cipher itself is very simple , and here is an example. (Images are not allowed) | | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | |----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|----|----| | 1 | 1 | 1 | F | | F| M | F | M | F | F | | | F | 4 | F | F | | 2 | F | 1 | F | 2 | | F | F | F | | M | F | M | 3 | F | F | | | 3 | F | M | | | | | | | | | | | | | | | | 4 | | | | | | | | | | | | | | | | | | 5 | | | | | | | | | | | | | | | | | | 6 | | | | | | | | | | | | | | | | | | 7 | | | | | | | | | | | | | | | | | | 8 | | | | | | | | | | | | | | | | | | 9 | | | | | | | | | | | | | | | | | | 10| | | | | | | | | | | | | | | | | | 11| | | | | | | | | | | | | | | | | | 12| | | | | | | | | | | | | | | | | | 13| | | | | | | | | | | | | | | | | | 14| | | | | | | | | | | | | | | | | | 15| | | | | | | | | | | | | | | | | | 16| | | | | | | | | | | | | | | | |

F->Flag

M-> Mine

The Image Clearly Represented Hidden/Open Cells as well but it is not possible with a table.

Idea

MineCipher converts any short sentence to a 16x16 MineSweeper Grid and encodes 6 bits of information per cell , which are represented as :

• Mine
• Number
• Hidden State (1=Opened,0=Closed)
• Flag

Total Capacity = 256 cells × 6 bits per cell = 1536 bits = 192 bytes

The Input ASCII String is first off converted to a stream of bits and divided into 6-bit chunks. Each of these 6 bit chunks is written onto a cell in row major order.

Code

def encode(sentence: str):
    """
    Encodes an ASCII string to a minesweeper grid of size 16x16 , storing 6 bits of information in each cell , making use of mine-state,
    number , hidden and flag states
    """

    bits=strToBits(sentence)
    mines=np.zeros((GRID_SIZE, GRID_SIZE), dtype=int)
    numbers=np.zeros((GRID_SIZE, GRID_SIZE), dtype=int)
    hidden=np.zeros((GRID_SIZE, GRID_SIZE), dtype=int)
    flags=np.zeros((GRID_SIZE, GRID_SIZE), dtype=int)

    index=0
    for row in range(GRID_SIZE):
        for col in range(GRID_SIZE):
            currBits=bits[index:index+CELL_BITS]
            # Mine
            mines[row,col]=int(currBits[0])
            # Number
            numbers[row,col]=((int(currBits[1])<<0)|(int(currBits[2])<<1)|(int(currBits[3])<<2))
            # Hidden
            hidden[row,col]=int(currBits[4])
            # Flag
            flags[row,col]=int(currBits[5])
            index+=CELL_BITS

    return mines,numbers,hidden,flags

def strToBits(sentence: str) -> np.ndarray:
    bits=[]
    for ch in sentence:
        code=ord(ch)  
        for i in range(7,-1,-1):
            bits.append((code>>i)&1)

    bitArray=np.array(bits,dtype=np.uint8)

    if len(bits)<TOTAL_BITS:
        padding=TOTAL_BITS-len(bits)
        bitArray=np.concatenate((bitArray,np.zeros(padding,dtype=np.uint8)))

    return bitArray

def decode(mines:np.ndarray,numbers:np.ndarray,hidden:np.ndarray,flags:np.ndarray)->str:
    """
    bit mapping:
      • bit 0 = mines[row,col]
      • bits 1–3 = numbers[row,col] (0..7)
      • bit 4 = hidden[row,col]
      • bit 5 = flags[row,col]
    """
    GRID_SIZE=16
    CELL_BITS=6
    TOTAL_CELLS=GRID_SIZE*GRID_SIZE
    TOTAL_BITS=TOTAL_CELLS*CELL_BITS
    bits=np.zeros(TOTAL_BITS,dtype=np.uint8)
    index=0

    for row in range(GRID_SIZE):
        for col in range(GRID_SIZE):
            #Mine
            bits[index]=int(mines[row,col])
            #Number
            val=int(numbers[row,col])
            bits[index+1]=(val>>0)&1
            bits[index+2]=(val>>1)&1
            bits[index+3]=(val>>2)&1
            #Hidden
            bits[index+4]=int(hidden[row,col])
            #Flags
            bits[index+5]=int(flags[row,col])
            index+=CELL_BITS

    bytesL=[]
    for i in range(0,TOTAL_BITS,8):
        byte=0
        for offset in range(8):
            bit=bits[i+offset]
            byte=(byte<<1)|bit
        bytesL.append(byte)

    raw=bytes(bytesL) 
    stripped=raw.rstrip(b"\x00")
    decoded=stripped.decode("ascii", errors="ignore")

    return decoded

Example

Final Hint for the Initial Image, these are the raw layers for each of our parameters:

               mines
 [[0 0 0 1 0 1 0 1 0 1 0 1 0 0 1 1]
 [0 0 0 0 0 0 0 1 0 1 0 1 0 0 0 1]
 [0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]

             numbers
 [[1 1 0 4 3 1 0 6 3 5 1 0 3 4 4 2]
 [3 1 0 2 3 5 3 0 5 5 6 1 3 5 0 5]
 [2 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]

            hidden
 [[1 1 0 0 1 1 0 1 1 1 0 0 1 1 0 1]
 [0 1 0 1 0 1 0 0 0 1 0 1 1 1 0 0]
 [1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]

               flags
 [[0 0 1 0 1 0 1 0 1 1 0 0 1 0 1 1]
 [1 0 1 0 0 1 1 1 0 0 1 0 0 1 1 0]
 [1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
 [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]

The Encoded String was:

I do not like JavaScript..