A method for supporting sharing of travel history of travelers in airports, wherein the travelers' identity is managed using a distributed ledger system, wherein the distributed ledger system includes a global identity blockchain and several per segment security blockchains, wherein the global identity blockchain is accessible by entities of the distributed ledger system, and wherein a per segment security blockchain is employed for a predetermined flight segment, such that the per segment security blockchain is accessible only by entities of the distributed ledger system that are involved in the predetermined flight segment, the method comprising the steps of: a) generating a history secret of a traveler according to a resistance mechanism for resisting a creation of multiple identities, in particular a Sybil-resistance mechanism; b) receiving, by the global identity blockchain, a registration request of the traveler, wherein the registration request comprises a commitment of the traveler's history secret, and wherein the global identity blockchain verifies the validity of the commitment; c) receiving, by the per segment security blockchain, a ticket transaction that is issued by an airline entity, wherein the ticket transaction comprises information on the identity of the traveler and information on the time of journey; d) recording, by the per segment security blockchain, a share travel history request from the traveler, wherein the share travel history request comprises a partial history secret, and wherein the per segment security blockchain verifies the validity of the partial history secret; e) using, by an entity of the per segment security blockchain, the partial history secret to retrieve the travel history of the traveler; f) creating, by the per segment security blockchain, a flight report at the end of a flight to add said flight to the travel history of all travelers of said flight; g) employing a hash-chain, which is only extendable, for representing travel history updates of the traveler. wherein the distributed ledger system includes a global identity blockchain and several per segment security blockchains, wherein the global identity blockchain is accessible by entities of the distributed ledger system, and wherein a per segment security blockchain is employed for a predetermined flight segment, such that the per segment security blockchain is accessible only by entities of the distributed ledger system that are involved in the predetermined flight segment, a) generating a history secret of a traveler according to a resistance mechanism for resisting a creation of multiple identities, in particular a Sybil-resistance mechanism; b) receiving, by the global identity blockchain, a registration request of the traveler, wherein the registration request comprises a commitment of the traveler's history secret, and wherein the global identity blockchain verifies the validity of the commitment; c) receiving, by the per segment security blockchain, a ticket transaction that is issued by an airline entity, wherein the ticket transaction comprises information on the identity of the traveler and information on the time of journey; d) recording, by the per segment security blockchain, a share travel history request from the traveler, wherein the share travel history request comprises a partial history secret, and wherein the per segment security blockchain verifies the validity of the partial history secret; e) using, by an entity of the per segment security blockchain, the partial history secret to retrieve the travel history of the traveler; f) creating, by the per segment security blockchain, a flight report at the end of a flight to add said flight to the travel history of all travelers of said flight; g) employing a hash-chain, which is only extendable, for representing travel history updates of the traveler.