Steganography API at your service.

Steganography is the art and science of embedding secret messages in a cover message so that no one, apart from the sender and intended recipient, suspects the existence of the message. 

The most common example is to hide a message in an image file without compromising how the image looks. The majority of the people are using the photos to share a fantastic moment or two and don’t know that they can contain a secret message.

What could be the use-case?

Someone can hack your phone and embed your text messages in the pictures you take and share in, say, Instagram. 

A not so happy employee can post a picture on your blog with a secret message embedded in it to share some trade secrets with your competitors. 

Another person can embed an exploit in a PNG ads image; JavaScript code would parse the PNG image, extract the malicious code, and redirect the user to the exploit kit landing page.

Steganography also is a well know method for exchanging information between spies. 

Even if it sounds like science fiction, this is a very viable threat against your systems and you.

Steganography Protector API

I have created a small API (as a Proof of concept) that could discover a secret message hidden in any image file.  

The end-point is here:

It accepts POST requests only. 

The input should be JSON encoded, and it should consist of a binary stream of your image.

Here is a Python example.

import requests
url = '' 
my_img = {'image': open('secret.png', 'rb')}
r =, files=my_img) 

The result of the command can be:

{'message': 'Secret Message', 'status': 'sucess'}

I am planning to extend the API by adding more use-cases and documentation, but if you are free to start using it right away.

If you have any questions about it or it seems down, contact me via Twitter – @bogomep

A practical use

You could read all of your images from your blog and via the API to check whether they contain a secret message or not or to check for hidden traces of your last Instagram image.

If you are looking for a picture with a secret message inside – why don’t you test this one:

Involve your team members when you do your threat modeling.

Most of the companies I worked for or know about have a bizarre threat modeling process. They count on the architect or the most knowledgeable person to do the threat modeling. It’s defined as a one-person job!

If your goal is to do it, because it’s one of the required artifacts for your service to go in production or any other stage, it may be the right approach. But this is no threat modeling; it’s a false sense of security. You call for harmful attempts against your system because you put all the eggs in one basket. 

It’s the exact opposite of the goal of a threat modeling session.

Involve your team members when you do your threat modeling.

Every person in your team has a unique perspective and a way of thinking about possible threats against any system. 

Every person has a different experience compared to the others. 

Every person has different emotions and morale. 

All of those qualities play a critical role in the threat modeling process.

Let me give you an example:

I started a fun and useful exercise, explaining the threat modeling goal by bringing people together in front of a virtual whiteboard and doing a threat modeling against a beer tap infrastructure. 

The challenge

We have a yard with a few doors to enter it. We also have the beer tap, a pressure system, key storage, and some power controls. We have two boundaries to protect.

The team members were encouraged to “go wild” and think just for 7 min about all possible threats they see against the infrastructure individually. 

Then I asked them to put virtual “sticky” notes near the components that could be threatened and discuss the findings as a team.

I did that with six groups from different geo-locations, and every time, I received different results. 90% of the threats were common, but 10% of them differed from group to group. This is how you make your modeling better.

To compare, I asked a few people to do this exercise alone for the same time, and the difference I saw was that the wisdom of the crowd identified with 40% more threats than a single individual. If this is not hard proof, which is it?

Involve your team members when you do your threat modeling. It’s the first step into your journey towards creating a bit more secure products.

Hiking Near Prague: Třebsín

One of our favorite short hiking walks (3-4h) near Prague starts from a small village called Třebsín .

The route.

Stop the car* by the pub – usually, there are around 20 car spots. Then follow the green route towards “ Závist u Třebsína .”

You might see most of the people going to another direction, but I recommend you not to follow them. The reason I’ll explain later.

So, find the green path and walk a bit up-hill for 0.5 kilometers. You will pass this magnificent view.

After a while, the road will end, and you will start walking into a fantastic forest. Keep walking for another 2.5 kilometers. Make sure you read all the signs along the path to learn more about the area. In the end, you will find the next stop called ” Medník .

A view from the forest

Then continue to the green path to “Na Stezce.”

The green path :)

At some point, you will feel the 15 min downhill experience, which was the main reason not to take the trace the other way around as most of the people did :) I saved you! :)

When you reach “Na Stezce”, change the color and start following the “red” path towards “Pod Třebšínem

You will pass lots of bungalows and friendly-looking people and a lovely pub, which is closed due to the COVID lockdown. Then you will see some beautiful views from Sazava River like the one that we took with our cameras. Just follow the road and be kind to nature and to the people you meet.

Here you can sit and observe the nature
A nice view from the route

When you reach “Pod Trebsinem” retake the green path for another kilometer to go back to Třebsín .

Don’t forget to stop by here and read more about the name of the village. It’s a pretty exciting story, but since my Czech is very limited, I liked the way they presented it more :)

A story about the village,

* I use my car to drive somewhere and to discover routes that start and finish at the same spot.