A method and system for determining a cost to allow a blockchain-based admission to a protected entity. The method includes identifying, in a blockchain network, a conversion transaction identifying a conversion of a first-type of access tokens with access tokens of a second-type, wherein the transaction designates at least the protected entity; determining a conversion value for converting the first-type of access tokens into the second-type access tokens, wherein the conversion value is determined based on at least one access parameter; and converting, based on the determined conversion value, a first sum of the first-type access tokens into a second sum of the second-type access-tokens, wherein a client spends the second sum of the second-type access tokens to access the protected entity, the determined conversion value is the access cost to the protected entity.