The document proposes a permutation-based algorithm for encrypting images where each pixel is swapped with a randomly generated value to encrypt the image without compromising speed, time, or information. It uses pseudo-random number generators and linear congruential generators to generate random numbers for shuffling pixel rows and columns. The decryption process repeats the encryption steps in reverse order to recover the original image. The algorithm works in linear time and is adaptable by changing block size or pseudo-random number generator parameters, allowing for different encrypted images. It tests the algorithm on images of different sizes using different block lengths.

2. • With the escalating use of internet technology, the exigency for security of valuable
information becomes of utmost importance.
• Our aim is to provide an efficient way of encrypting images where the speed, time or
information are never compromised. Therefore in our paper we present a permutation
based algorithm where each pixel of the image is swapped with the corresponding
generated random value using pseudo random number generators.

3. Step 1: LCG
STEP 2: LFG
ARRAY OF
PSEUDO
RANDOM
NUMBERS
• Iteration through all
the rows shuffling
them using random
stream from previous
step
• Iteration through all
the columns shuffling
them using random
stream from previous
step

4. 1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
16 17 18 19 20
21 22 23 24 25
966558 75961 2239 25424 42073
3 0 2 1 4
Modulus of random
numbers with
image size
In order to attain
random numbers in
a specific range
Modulus of random
numbers with
image size
In order to attain
random numbers in
a specific range
2 4 0 1 3
57643 3424 21156 69078 13167
6 9 8 10 7
1 4 3 2 5
11 14 13 12 15
21 24 23 22 25
16 19 18 17 20
Row Shuffle Column Shuffle

5. • The decryption process is exactly similar to the encryption process. One
has to repeat the steps backwards in order to attain the original
image(Backtracking).

6. • Our algorithm works in linear time. In the sense that instead of rows*columns it is
rows+columns which reduces the encryption time
• Our algorithm is adaptable and flexible. By changing some parameters like the block
size, or the PRNG parameters we get a different encrypted image. Therefore leading
to a plethora of possibilities

7. We make use of 3 different images and pass them through the encryption
process with each having different block size.

8. • An image of size 1440 × 1280 pixels is encrypted using the algorithm. The private key
parameters for both encryption and decryption are set as follows:
J=418; k=1279
: a=1664525; m=2**32; c=1013904223
• Block length value: 1

9. • An image of size 2560 × 1600 pixels is encrypted using the algorithm. The private key
parameters for both encryption and decryption are set as follows:
: J=418; k=1279
a=1664525; m=2**32; c=1013904223
• Block length value: 8

10. • An image of size 1440 × 1280 pixels is encrypted using the algorithm. The private key
parameters for both encryption and decryption are set as follows:
J=418; k=1279
a=1664525; m=2**32; c=1013904223
• Block length value: 4