17 Dec
2003
17 Dec
'03
11:17 p.m.
On Fri, 29 Jul 1994, Adam Shostack wrote:
A filename and length give away the fact that something is hidden. If you only hide encrypted data, and no plaintext of any sort, then the file can not be automatically detected; it can ony be seen by someone who can decrypt it.
... well almost. It's trivial to write a program that extracts the LSB's from a GIF file and then determine their randomness. Truly random data gives away the presence of an encrypted file. The solution is to choose the LSB's that you alter according to the output from a decent random number generator so that each LSB has a probability of being altered. - Andy