What is the code in the Back of the Dan Brown book "Digital Fortress"? On the last page after the epilogue, there is a code or some numbers that look like a code. What is it? If it is a code, how can I solve it?

The numbers should be 128-10-93-85-10-128-98-112-6-6-25-126-39-1-68-78 with each number corresponding to a different chapter. Use these numbers to find the first letter on each chapter, which should get you W E C G E W H Y ......(I don't want to spoil it). Then arrange them in ceasars box which should give you a 4x4 grid as you will have 16 letters. The first row would be WECG then the second row EWHY etc. Then you just need to read downwards