Independent verification using third-party tool (xxhsum)
to prove Master Copy's reliability.
Is your copy really safe?
macOS standard tools (Finder, cp) don't verify after copying. Even if errors occur or files are corrupted, you won't know.
Example: During a 100GB video copy, if even 1 byte has an error, the file is unusable. But Finder shows "Copy Complete."
Master Copy calculates xxHash128 checksum while copying. Copy complete = Verification complete. Errors are immediately notified.
Benefit: Zero additional time for verification. The moment copying finishes, you know "this file is correct."
What if Master Copy is just saying "hash matched"?
We can't trust something that verifies itself.
Independent verification with third-party tool
141.42 GB of video data (10 files) copied with 3 different tools:
Not using Master Copy's built-in verification, but an independent third-party tool "xxhsum 0.8.3" (by Yann Collet).
Calculate hash values with xxhsum for all files copied by the 3 tools, and verify if they match the original file hashes.
# Calculate hash of original files$ xxhsum source/*9d8d40332ad8c1be8d070029fa7a6cbe# Hash of files copied with Master Copy$ xxhsum dest_mastercopy/*9d8d40332ad8c1be8d070029fa7a6cbe ✅ Match
100% match across all files and runs
Conclusion: All 3 tools showed perfect hash match verified by an independent third-party tool (xxhsum). The hash values calculated by Master Copy are accurate, proving that files are copied correctly.
Verified on real production equipment
All evidence published on GitHub
Report JSON, verification scripts, and complete logs published on GitHub.
Viewable in browser (no account required). Version history available.
$ bash verify_signature.sh✅ Signature valid
$ jq '.verification' report.json"all_hashes_match": true
Near cp-level speed
Key Point: Master Copy verifies while copying, so no additional time is needed. The moment copying finishes, you know it's "correct."
Reliability proven by independent third-party verification.
Try the free beta today.