i think that Bitonic Sorting can be used as a trapdoor function, more or less.
When properly done, amateur programmers without costly parallel machines won't be able to efficiently sort data... and such sorting can be part of a decryption algorithm.
This would eliminate most of 'amateurs' as possible decryptors to be checked for breaking a cipher. Only people with knowledge & resources - usually companies - would be able to break that kind of cipher.
i think that sensitive data encrypted that way is no match for real Intelligence Agencies, but would save many people a worry of a data being leaked during transmission to most of other individuals, most of companies & most of institutions.