How to encrypt a graph

• Published in: International journal of parallel, emergent and distributed systems Vol. 35; no. 6; pp. 668 - 681
• Main Author: Akl, Selim G.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 01-11-2020; Taylor & Francis Ltd
• Subjects: Algorithms; Apexes; ciphertext; confusion; cryptanalysis; Cryptography; cryptology; decryption; diffusion; Encryption; encryption algorithm; encryption scheme; graph; graph database; Graph theory; homomorphic encryption; malleability; Mapping; molecular encoding; multigraph; one-time key; one-way function; plaintext; public-key cryptosystem; quantum cryptography protocol; secret key; social networks; trapdoor one-way function; unconventional cryptographic function
• ISSN: 1744-5760; 1744-5779
• DOI: 10.1080/17445760.2018.1550771

An algorithm is described for encrypting a graph to be transmitted securely from a sender to a receiver. In communications terminology, "the graph is the message": its vertices, its edges, and its edge weights are the information to be concealed. The encryption algorithm is based on an unconventional mapping, conjectured to be a trapdoor one-way function, designed for graphs. This function requires the sender and the receiver to use a secret one-time encryption/decryption key. It is claimed that a malicious eavesdropper with no knowledge of the key will be faced with a computational task requiring exponential time in the size of the input graph in order to extract the original plaintext from the ciphertext carried by the encrypted graph. A number of variants to the main algorithm are also proposed.