1. A method, comprising: receiving, at a client-side web browser, a minimal bootstrap payload from an application server; storing, by the client-side processor, the minimal bootstrap payload in the client-side local cache, wherein the locally cached minimal bootstrap payload is executed by the client-side processor before executing an application from the application server; the minimal bootstrap payload includes at least one public key, at least one Uniform Resource Location (URL) address of an application code payload, a second URL and a backup URL; the client-side processor executes the minimal bootstrap payload, which comprises: receiving, at the client-side web browser, the application code payload from the URL specified by the minimal bootstrap payload, wherein the received application code payload includes a cryptographic signature that was generated using a private key associated with a public key specified by the minimal bootstrap payload; verifying, by the client-side processor, the received application code payload cryptographic signature using a locally stored public key; executing, by the client-side processor, the received application code payload after the received application payload has been successfully verified; receiving a cryptographically signed pre-computed hash from the second URL, verifying, by the client-side processor, the received pre-computed hash using a locally stored public key; storing, by the client-side processor, in the client-side local cache a copy of the verified pre-computed hash with or without its associated signature; and receiving a backup application code payload from a backup URL when the minimal bootstrap payload fails to verify the received application code payload cryptographic signature using a locally stored public key.