Method for performing an electronic transaction, comprising the following steps: a) a first user client digitally sending to a first node transaction information, which transaction information comprises a first user predictable transaction counter, which is unique for the combination of the first user and the electronic transaction in question; and a user transaction state digest, which is the output of a one-way function calculated based on at least an immediately preceding electronic transaction registered in relation to the first user; b) the first node affirming the transaction information; c) the first node digitally communicating the transaction information to additional nodes (160,170) on an electronic transaction network of such nodes; d) at least one of said additional nodes (160,170) affirming the transaction information; e) one or several nodes verifying that at least a predetermined number of nodes have affirmed the transaction information; and f) one or several nodes registering a transaction based upon said transaction information and digitally disseminating information to all nodes (150,160,170) on said network regarding positive affirmation status of at least said predetermined number of nodes, wherein each of said first and additional nodes (160,170) comprises information regarding a previous first user transaction counter as well as regarding an updated user transaction state digest, and that said affirming comprises both verifying that said first user transaction counter matches an expected value thereof and that verifying that said user transaction state digest matches said updated user transaction state digest, by comparison to said information in the node (150,160,170) in question; and wherein the user transaction state digest is calculated as the last calculated result of a chain of one-way function calculations, so that a separate transaction chain, interlinked by the user transaction state digest, is constructed and maintained by each of said first and additional nodes (160,170), for each individual user. a) a first user client digitally sending to a first node transaction information, which transaction information comprises a first user predictable transaction counter, which is unique for the combination of the first user and the electronic transaction in question; and a user transaction state digest, which is the output of a one-way function calculated based on at least an immediately preceding electronic transaction registered in relation to the first user; b) the first node affirming the transaction information; c) the first node digitally communicating the transaction information to additional nodes (160,170) on an electronic transaction network of such nodes; d) at least one of said additional nodes (160,170) affirming the transaction information; e) one or several nodes verifying that at least a predetermined number of nodes have affirmed the transaction information; and f) one or several nodes registering a transaction based upon said transaction information and digitally disseminating information to all nodes (150,160,170) on said network regarding positive affirmation status of at least said predetermined number of nodes, wherein each of said first and additional nodes (160,170) comprises information regarding a previous first user transaction counter as well as regarding an updated user transaction state digest, and that said affirming comprises both verifying that said first user transaction counter matches an expected value thereof and that verifying that said user transaction state digest matches said updated user transaction state digest, by comparison to said information in the node (150,160,170) in question; and wherein the user transaction state digest is calculated as the last calculated result of a chain of one-way function calculations, so that a separate transaction chain, interlinked by the user transaction state digest, is constructed and maintained by each of said first and additional nodes (160,170), for each individual user.