You can imagine generating an encrypted file 10^3 or 10^6 times larger than the data to be encrypted, with a pointer at the beginning giving the location of the start of the payload. The rest of the file could be encrypted randomness.
Transfer would be super slow but presumably the extreme file length would hinder decryption of the payload.
Of course the whole scheme would break down if the adversary knew the length/position of the pointer data.
You can do some really cool cryptography if you assume your adversary has limited space. Examples include non-transferable signatures and streaming programs that stop functioning when the stream stops (repugnant as a DRM but neat as a concept)
Transfer would be super slow but presumably the extreme file length would hinder decryption of the payload.
Of course the whole scheme would break down if the adversary knew the length/position of the pointer data.
Security through size?