Skip to content Skip to navigation Skip to collection information

OpenStax-CNX

You are here: Home » Content » Elec 301 - Steganography - What's In Your Picture? » Bit-O-Steg Hiding

Navigation

Lenses

What is a lens?

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

This content is ...

Affiliated with (What does "Affiliated with" mean?)

This content is either by members of the organizations listed or about topics related to the organizations listed. Click each link to see a list of all content affiliated with the organization.
  • Rice University ELEC 301 Projects

    This module is included inLens: Rice University ELEC 301 Project Lens
    By: Rice University ELEC 301As a part of collection: "ELEC 301 Projects Fall 2005"

    Click the "Rice University ELEC 301 Projects" link to see all content affiliated with them.

  • Rice Digital Scholarship

    This module is included in aLens by: Digital Scholarship at Rice UniversityAs a part of collection: "ELEC 301 Projects Fall 2005"

    Click the "Rice Digital Scholarship" link to see all content affiliated with them.

Also in these lenses

  • Lens for Engineering

    This module is included inLens: Lens for Engineering
    By: Sidney BurrusAs a part of collection: "ELEC 301 Projects Fall 2005"

    Click the "Lens for Engineering" link to see all content selected in this lens.

Recently Viewed

This feature requires Javascript to be enabled.
 

Data Hiding Methods

Bit-O-Steg

Hiding Information

As you should recall, our zeros hiding method inserts data into the dropped coefficients of the DCT. The bit-o-steg algorithm hides data within the coefficients that were not dropped. The critical part of bit-o-steg is the key used to encrypt the data. This user defined key selects which nonzero coefficients to change and which bits to change within each coefficient. The simplest key would be a key of [1]. This would change each coefficient sequentially and change the last bit in the coefficient.

Figure 1: The key is what makes bit-o-steg unique from other algorithms. Here a key of [1 2] is applied to hide the data.
Figure 1 (bit-o-steg_key)

As you can see in figure 1, we chose a key of [1 2]. The key will select the first coefficient and its least significant bit and input the first bit of the hidden data into that coefficient bit. Then the key will count two coefficients and take the second least significant bit and repeat the hiding process. Since this is the end of the key, it repeats, selecting the next coefficient. The length of this key has no real bound, but it must ensure that all data is hidden before reaching the last DCT coefficient in the image. There is, however, a range of values that must be selected for the key to work. Since the key alters bits, values between one and eight must be used. However, if larger values are used, it will alter the image greatly since it changes more and more significant bits.

Figure 2: Minimal changes have been made to the picture matrix after the application of the bit-o-steg algorithm
Figure 2 (bit-o-steg_result)

Retrieving the Data

Retrieving the data is impossible unless you have the special key used to hide the data. Once you get the key you simply reverse apply the key, extracting rather than inputting the bits and reconstruct your hidden data stream from those bits.

Collection Navigation

Content actions

Download:

Collection as:

PDF | EPUB (?)

What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

Downloading to a reading device

For detailed instructions on how to download this content's EPUB to your specific device, click the "(?)" link.

| More downloads ...

Module as:

PDF | More downloads ...

Add:

Collection to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks

Module to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks