1. A computer implemented method comprising: receiving, by a trust mediator included in an issuer network and having a processor, a list of protection methods from a first external terminal over a communication network, wherein the list of protection methods includes protection methods available to the first external terminal; matching, by the trust mediator, each of the protection methods in the received list of protection methods to a corresponding protection method in a master list of protection methods stored in a protection method database, wherein the master list of protection methods includes category information and strength information corresponding to each protection method; creating, by the trust mediator, a matrix of protection methods based on at least one of the matched protection methods, the matrix including a plurality of dimensions corresponding to a plurality of categories, respectively, wherein the protection methods are arranged in the matrix based on the category information, and, within each dimension, the protection methods are arranged based on the strength information; assigning, by the trust mediator, a first index level to a first protection method in the matrix, and a second index level to a second protection method in the matrix; receiving, by the trust mediator, security-related information from one or more trust mediator agents over the communication network, wherein the security-related information indicates that the first protection method is invalid; increasing, by the trust mediator and in response to the receiving the security-related information, a threshold index level; performing, by the trust mediator, a database lookup using an external terminal identifier for the first external terminal; retrieving, by the trust mediator and based on the external terminal identifier, rules corresponding to the received security-related information from a master list of rules; selecting, by the trust mediator, at least one protection method from the matrix of protection methods based on the rules obtained by the retrieving, the category information, the strength information, and the second index level, wherein the second index level is greater than the threshold index level; and transmitting, by the trust mediator, the at least one selected protection method to a trust mediator agent to complete a financial transaction.