A fast double-keyed authenticated image encryption scheme using an improved chaotic map and a butterfly-like structure

Authenticated image encryption is crucial in handling top-secret images. To ensure confidentiality, authenticated encryption supplies legal validity for the image data. We propose a novel modified logistic map with an expanded key space, an integer-based key generation algorithm and an authenticated image encryption algorithm for block ciphers using a modified logistic map and a butterfly-like structure. The key that is used to encrypt images also aids in detecting content tampering of the images. The performance evaluations demonstrate that the proposed encryption method is fast and invulnerable to attacks and has a large key space. Additionally, the designed algorithm can assess the credibility of the data. Moreover, eight keys are used in decryption compared to four in encryption, which strengthens the security. Therefore, this algorithm can be used in real-time scenarios.