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A comment on Show HN: Encrypt and hide files inside images. Parent comment

Re:Show HN: Encrypt and hide files inside images by hayst4ck on Wednesday October 26, 2022 @02:54AM (#33340603)
The concept is lossless vs lossy compressions. Facebook is known to do all manner of lossy transformations on images, while whatsapp likely (definitely if you believe it is e2e encrypted) would just transfer the bits.

Re-sizing would trash the payload, but any type of conversion that losslessly preservers the raster (the matrix of pixels) would likely still be recoverable.

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Re:Show HN: Encrypt and hide files inside images by codetrotter on Wednesday October 26, 2022 @03:16AM (#33340723)
> whatsapp likely (definitely if you believe it is e2e encrypted) would just transfer the bits

They could still compress images on the client side before sending the message. Dunno if they do or not, didn’t check. Just saying that E2EE does not prevent them from doing so.

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Re:Show HN: Encrypt and hide files inside images by milosmns on Wednesday October 26, 2022 @06:48AM (#33341933)
They do, you can choose a level but they still do. Document sending is uncompressed though, but won't generate a thumbnail in the chat
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Re:Show HN: Encrypt and hide files inside images by Ecstatify on Wednesday October 26, 2022 @03:15AM (#33340716)
WhatsApp compresses the image/video on the device before sending.

Example video 13.2MB => 7.2MB

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Re:Show HN: Encrypt and hide files inside images by n-i-m-a on Wednesday October 26, 2022 @03:54AM (#33340975)
you can choose to send as document/uncompressed.
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