As acknowledged also on Wikipedia, one of the drawbacks of ranked choice voting is that "it is likely that many preference voting patterns will be unique to individual voters, which could allow voters to identify themselves in a context of corruption or intimidation, undermining the secrecy of ballots".
For instance, candidate A, could offer 20$ to voter X to vote for candidates ABCDEFG in this exact order, 20$ to voter Y to vote for ABCDEGF, and 20$ to voter Z to vote for ABCDGFE; then, since these orderings are unique and unlikely to happen by chance, they can verify that each one of the bribed people voted as instructed.
Since the number of orderings is large and choices past the first few don't matter, this allows for large-scale vote buying, by giving a different unique ordering to each bribed voter. The problem can be mitigated by limiting choices on the ballot to a small number, for instance 3, but with a large number of candidates even this does not help much.
Is there a ranked voting variant that could prevent this, without introducing other more serious drawbacks? Maybe something is possible using cryptography? Or is this an open problem in the context of ranked voting?