signed
Parameters
value
Limit how far into the future the expiration time of a signed request may be. When set, a signed request is rejected if its expiration time is later than now + signedRequestMaximumExpirationTtl, where now is the time at which the signed request is first handled by the CDN.
The TTL must be 0.
Fractions of a second are not allowed. By default, signedRequestMaximumExpirationTtl is not set and the expiration time of a signed request may be arbitrarily far into future.