Also of note is that some government standards for data destruction (e.g., NIST and NISPOM) specifically require that files be overwritten with a certain pattern, and even multiple times for different security levels. So those sites who have to comply with such standards won't be able to use an encryption-only solution to discard data. The other problem with crypto on persistent media is that you can't easily predict how secure data will be in the really long run, say years or decades. Suppose an attacker manages to get their hands on a crypto disk whose keys were destroyed. With today's technology, the attacker might not be able to break the crypto. But wait 10 years, and who knows what kinds of computing powers we will have then. (Even ten-year old data, if recovered, could still be highly valuable -- eg., top-secret military files). Crypto is great. But overwriting data even just a couple of times w/ random bits, elevates the level of attack required to recover such data, well past crypto. Erez. - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
