green_meklar t1_jbcyjm2 wrote on March 8, 2023 at 3:33 AM

Reply to comment by zalgorithmic in A group of researchers has achieved a breakthrough in secure communications by developing an algorithm that conceals sensitive information so effectively that it is impossible to detect that anything has been hidden by thebelsnickle1991

The problem with encrypted data that looks like noise is that noise also looks like encrypted data. If someone sees you sending noise to suspicious recipients, they can guess that you're sending encrypted messages. Governments that want to ban encryption or some such can detect this and stop you.

The advantage of steganography is that you can hide not only the message itself, but even the fact that any encryption is happening. Your container no longer looks like noise; it's legitimate, normal-looking data with a tiny amount of noisiness in its structure that your recipient knows how to extract and decrypt. It gives you plausible deniability that you were ever sending anything other than an innocent cat video or whatever; even people who want to ban encryption can't tell that you're doing it.

zalgorithmic t1_jbczvnb wrote on March 8, 2023 at 3:44 AM

In my mind it’s best to do:

Data->compress->encrypt->steganography

Not saying steg is bad and cryptography is good, just that I don’t quite see how encrypting the data properly in the first place such that it shows up as some random distribution before embedding it with steganography is a wildly new concept.

If the distribution of encrypted data is that of noise, the image would just appear slightly noisy, especially if doing least significant bit shenanigans

green_meklar t1_jc51rar wrote on March 14, 2023 at 2:13 AM

>I don’t quite see how encrypting the data properly in the first place such that it shows up as some random distribution before embedding it with steganography is a wildly new concept.

It's not. I was getting at the converse idea: Given your encrypted data, steganography allows you to hide the fact that any encryption is even being used.

>If the distribution of encrypted data is that of noise, the image would just appear slightly noisy

Only by the broadest definitions of 'noise' and 'appear'. The image does not need to actually have visual static like a dead TV channel. That's a very simple way of embedding extraneous data into an image, but not the only way.