1. A method comprising: establishing, over a communication channel, an initial trust between a first computing device and a second computing device; and refreshing the initial trust by performing at least the following: receiving, by the first computing device and from a trusted authority, a first non-repeating authenticator that is unique to the first computing device and configured to be validated by the second computing device; signing, by the first computing device and using a first key associated with the first computing device, a first message, wherein the first message comprises the first non-repeating authenticator and a first header parameter; sending, by the first computing device and to the second computing device, the signed first message; receiving, by the first computing device and from the second computing device, a signed second message, wherein the signed second message comprises a second non-repeating authenticator that is unique to the second computing device and configured to be validated by the first computing device; and validating, by the first computing device, the signed second message, wherein the validating is based on: validating the second non-repeating authenticator, and using a second key associated with the second computing device.