The security parameter k is set to 2160 blocks. The code comment describing this genesis parameter makes it crystal clear it defines the maximum number of blocks the chain could potentially roll back. 2160 blocks equals 43,200 slots, or 12 hours.
The Ouroboros security parameters, aka k. This is the maximum number of blocks the node would ever be prepared to roll back by.
Clients of the node following the chain should be prepared to handle the node switching forks up to this long.
and the description in CIP#9
After how many blocks is the blockchain considered to be final, and thus can no longer be rolled back (i.e. what is the maximum allowable length of any chain fork).
to this article in the official docs
A transaction becomes immutable as soon as its depth is greater than 3k/f slots (that is, 129600 slots on current mainnet, or 36 hours).
Can someone please explain
what is the source for the docs to come up with this formula 3k/f
which statement is correct (12h or 36h), and why?