btw: On Sat, 2018-12-29 at 12:05 +0100, Jonas Meurer wrote: > So we wonder whether you (cryptsetup upstream would consider to make > discard the default in cryptsetup, at least for LUKS devices. I shall hope upstream doesn't decide so :-) > As far as we know, the main *negative* impact of enabling the trim > feature on flash devices is, that it might reveal information on > which > parts of the disk are written and which are not, even if you first > filled the disk with random data[2]. I'd expect it to be also a problem for non-SSDs,... just imagine a rogue chipset (on the bus, HDD, etc.) which intercepts the TRIMs with their potentially valuable information. > To our knowledge, that's only a > problem if you need plausible deniability, wich LUKS doesn't provide > anyway. AFAIK, this hasn't to do anything with plausible deniability (at least not in the classic sense of "hidden encryption"), but rather that an attacker might gain valuable information that can be used for further attacks... and as always it's likely just our imagination which limits these. One could think of deletion patterns that (depending on their size) give hint what is being deleted (what you might have meant by plausible deniability?)... or perhaps it could eventually somehow help in statistical attacks (maybe a regularly deleted file with more or less known content)? OTOH,... I'm not an expert cryptoanalyst... so others may have much more knowledge about all this :) Cheers! _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx https://www.saout.de/mailman/listinfo/dm-crypt
