Rclone on Synology DSM 7.3xx NAS with sync to MEGA Cloud
This post is of limited relevance, limited to Rclone users with Synology NAS for backup/sync to the MEGA Cloud.
It simply communicates my personal discovery of a recent ban and the recent incompatibility of Rclone, even in the latest version, due to recent restrictions implemented by MEGA, to anyone interested.
Without further ado, I discovered that Mega servers have implemented a cryptographic "Proof of Work" (PoW) or "Challenge-Response" mechanism to enhance API authentication.
In reality, before allowing actual login, the server sends a request for a complex mathematical problem based on cryptographic calculations that the client must solve using the local CPU. Only upon presentation of the correct result of the equation will the server accept the credentials.
This not only makes brute force attacks computationally expensive, but also blocks the current version of Rclone, which is not designed to solve this "mathematical challenge" by causing the connection to fail.
However, it would be interesting to know if this "challenge" can be taken up by Rclone and successfully overcome! Otherwise Rclone will no longer be able to work with Synology/DSM
rclone lsd mega: -vv
2026/02/17 17:07:01 DEBUG : rclone: Version "v1.73.1" starting with parameters ["rclone" "lsd" "mega:" "-vv"]
2026/02/17 17:07:01 DEBUG : Creating backend with remote "mega:"
2026/02/17 17:07:01 DEBUG : Using config file from "/var/services/homes/user99/.config/rclone/rclone.conf"
2026/02/17 17:07:01 DEBUG : mega root '': Using previously stored session ID and master key to initialize the Mega API
-1 2024-05-21 15:49:45 -1 zork
In my case, rclone worked perfectly with Mega Cloud until about ten days ago, uploading a terabyte overnight.
In the following days, due to a huge volume of mass deletions of @eadir directories I hadn't properly filtered before starting synchronizations, I believe rclone activities were banned, at least in my case.
Even with the latest version of rclone installed in the hope of circumventing the block, I contacted Mega and they told me they'd introduced some unspecified filters for "unauthorized and unsafe software."
Since then, I've never had access to rclone again, as it would be blocked upon login.
MEGAcmd, however, works perfectly. This comparison between the two software programs is just to confirm that on my end there are no limitations.
I'm not at the computer right now, but I'll post screenshots of Mega's responses to each connection attempt.