SpeakingJpg
Security and privacy
steganography
SHOW HN2017
How HN took it
1 positive, 2 neutral or asking, 0 mixed, 3 critical, out of 6 comments about the project. Thread score -0.21.
Privacy: 0 for, 2 againstIdea: 1 for, 0 againstExecution: 0 for, 1 against
The thread, comment by comment
Each row is a top-level comment and its replies, in HN's order. Select a cell to open that comment on HN.
positive neutral or mixed critical about another commenter or something else the maker
What HN said
What people liked
Fun to play with and a cool idea
From 2 comments
Cool, but it appears to embed in a jpeg comment section with a predictable constant that marks what it is. So fun to play with, but not terribly covert.
tyingq on HNReally cool! I actually read about this idea years ago in a book (Dean Koontz, The Husband iirc). Ever since then I've wondered why it isn't more common to try to obscure…
notheguyouthink on HN
Objections
Embedding in a JPEG comment block with a constant identifier is not covert
From 1 comment
Cool, but it appears to embed in a jpeg comment section with a predictable constant that marks what it is. So fun to play with, but not terribly covert.
tyingq on HN
Metadata gets stripped by online services that resize images
From 2 comments
Having text in the comment section does not seem very useful as most online services will resize the image and very likely strip comments (as mentioned in the readme). A…
Gys on HNAgreed, though that would require a lossless format (e.g. png) and would limit exchanges to sources that don't change the image (e.g.as email attachment) but not social networks…
wolframhempel on HN
Lossy JPEG recompression destroys LSB-style hidden data
From 2 comments
You was probably thinking about this: http://steghide.sourceforge.net/ It hides data in the least significant bits (at locations defined by a passphrase) of the image or audio…
drdaeman on HNYou don't have to use a lossless format for steganography, for example: 'Statistically Undetectable JPEG Steganography: Dead Ends, Challenges, and Opportunities'…
anfractuosity on HN
Requests
Make the identifier configurable or scan all comment blocks
From 1 comment
true - would make sense to make the identifier configurable and/or just iterate trough all comments in the jpg
wolframhempel on HN
Support multiple comment blocks to exceed the 65k limit
From 1 comment
The data is going in an APPn jpeg metadata block (jpg "comment"), max size of 65k. You could use multiple comment blocks, but this doesn't implement that.
tyingq on HN
Use a lossless format like SVG or PNG
From 2 comments
Having text in the comment section does not seem very useful as most online services will resize the image and very likely strip comments (as mentioned in the readme). A…
Gys on HNAgreed, though that would require a lossless format (e.g. png) and would limit exchanges to sources that don't change the image (e.g.as email attachment) but not social networks…
wolframhempel on HN
Questions
What is the 65k limit due to
From 1 comment
Nice, I haven't looked at the code yet, but I'm curious what the 65k limit is due to? I was just thinking though, if you're using the meta data field, couldn't that make it…
anfractuosity on HN
Is hiding data in metadata obvious
From 1 comment
Nice, I haven't looked at the code yet, but I'm curious what the 65k limit is due to? I was just thinking though, if you're using the meta data field, couldn't that make it…
anfractuosity on HN
Alternatives named
Steghide
From 1 comment
You was probably thinking about this: http://steghide.sourceforge.net/ It hides data in the least significant bits (at locations defined by a passphrase) of the image or audio…
drdaeman on HN
OpenStego
From 1 comment
https://en.wikipedia.org/wiki/Steganography I remember being told that Al-Qaeda used this mechanism to exchange messages pre-9/11. Surely there are longer established tools for…
scandox on HN
ImageMagick stegano option
From 1 comment
>where the encrypted message is overlayed into the picture data You can play around with this idea using imagemagick. It has a built it "stegano" option to hide one image within…
tyingq on HN