Image Encryption/Decryption based on Rubik Cube 's principle and AES

Our final project for Theory of Crytography class.

Our Image Encryption/Decryption method based on:

• Rubik Cube principle (paper here)

• AES (Advanced Encryption Standard)

My implementation can be introduced by four main parts:

• Encryption
• Decryption
• Evaluation
• Result

Encryption

• Three channels of the image are splited before encrypting with Rubik cube algorithm. The key of the encryption is encrypted by AES.

• After that, these encrypted channels are combined to generate the Encrypted Image.

Decryption

The flow of decryption is the inverse transformation which is described below:

• Split the encrypted image to 3 encrypted channels

• Get the original key from the AES decrypt function

• Decrypt 3 channels with the decrypted key

The Encrypted Image

Evaluation

I propose two measures to quantify the differ between the encrypted image and its original form:

• Number of pixels change rate (NPCR)
• The unified average changing intensity (UACI)

Results

Original Image and Encrypted Image

Histogram