Secret codes and error-correcting codes have nothing to do with each other. Except when they do!
Error-Correcting Codes
Error correcting code makes digital communication possible. Without some way to detect and correct errors, the corruption of a single bit could wreak havoc. A simple example of an error-detection code is check sums. A more sophisticated example would be erasure codes, a method used by data centers to protect customer data against hard drive failures or even entire data centers going offline.