The binary is stripped, has no debugging symbols and is compiled with -fno-stack-protector and -no-pie . The name dvdes hints at (Data Encryption Standard) and the suffix 631 is a hint toward the key schedule (the 16‑round sub‑keys are derived from the 64‑bit key, each sub‑key being 48 bits – 6 bits per round × 16 = 96 bits ≈ 631 decimal when interpreted in octal).
$ file dvdes-631 dvdes-631: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, stripped dvdes-631
Running the unwind in Python (see unwind.py in the attached repo) yields: The binary is stripped, has no debugging symbols