This paper analyzes the security of the common distributed consensus algorithms used in smart city distributed ledgers. There is proposed a concept of smart city distributed ledgers protection, which applies a hybrid distributed consensus protocol based on the joint use of the tangle class algorithm and the proof-of-authority class algorithm, protected by trusted computing and remote attestation technologies. The proposed protocol compensates for the weaknesses and vulnerabilities of the conventional distributed consensus algorithms that are inherent in distributed ledger technology and hinder its widespread use in large-scale smart city systems