IZE
From Just Solve the File Format Problem
.ize is an encrypted file format presumably native to IZArc, an archiving application.
The documentation implies that it uses the AES-256 cipher.
The change log says that encryption was added in IZArc version 3.3.
Identification
Unknown. Some degree of heuristic identification might be possible by looking at the first few bytes, and the last 256 bytes.