Posts Tagged ‘Fingerprinting

Honeypots or decoy email addresses

Honeypots (decoy email addresses) are used for collecting large amounts of spam. These decoy email addresses do not belong to actual end users, but are made public to attract spammers who will think the address is legitimate. Once the spam is collected, identification techniques, such as hashing systems or fingerprinting, are used to process the spam and create a database of known spam. Let’s take a closer look at hashing systems and fingerprinting.

HASHING SYSTEMS: With hashing systems, each spam email receives an identification number,or “hash,” that corresponds to the contents of the spam. A list of known spam emails and their corresponding hash is then created. All incoming email is compared to this list of known spam. If the hashing system determines that an incoming email matches an email in the spam list, then the email is rejected. This technique works as long as spammers send the same or nearly the same email repeatedly. One of the original implementations of this technique was called Razor.

FINGERPRINTING: Fingerprinting techniques examine the characteristics, or fingerprint, of emails previously identified as spam and use this information to identify the same or similar email each time one is intercepted. These real time fingerprint checks are continuously updated and provide a method of identifying spam with nearly zero false positives. Fingerprinting techniques can also look specifically at the URLs contained in a message and compare them against URLs of previously identified as spam propagators.

Honeypots with hashing or fingerprinting can be effective provided similar spam emails are widely sent. If each spam is made unique, these techniques can run into difficulties and fail.

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Watermarking and Fingerprinting in the Transcoding Workflow

When you add the enormous accumulation of video content that resides inthe archives of media organizations to all of the new content that’s constantly being produced, you realize that sheer volume poses a significant challenge to utilizing both watermarking and fingerprinting technologies. At the very minimum, implementing an anti-piracy solution around watermarking requires the following capabilities:

For watermarking, consider whether to handle detection in-house orwhether to employ an outside service. The choice depends on how the watermark will be used. For example, to trace a single video back to its source should it be leaked, detection could be easily handled in-house. If your preference is to let someone else hunt down leaks, perhaps because they could come from a large number of would-be pirates, consider an external detection service.

Fingerprinting requires the following capabilities:

  1. Method to generate fingerprints
  2. Database to store metadata relating fingerprints to originals
  3. Third-party service (or multiple services) that tracks fingerprints and provides access control information

One of the problems with current watermarking and fingerprinting technologiesis that they only accept a limited number of input formats. And, in the case of watermarking, they only generate a limited set of output formats.  Plugging a particular watermarking or fingerprinting technology into Carbon Coder allows you to handle any media type. Carbon Coder can be run as a stand-alone transcoding engine or aspart of a larger transcoding farm for higher volume workflows.

Transcoding a media file from one video format to another involves a number of steps:

For the fastest execution, all of this occurs on-the-fly, in memory. In watermarking, the watermarking filter is plugged into the Carbon Coder pipeline and is applied during the transform stage. The result is a media file, in whatever format is required for distribution.

In fingerprinting, the fingerprint technology is embedded into Carbon Coder as an exporter. It analyzes the uncompressed audio and video frames and generates a fingerprint file, which can be used to recognizethe original media, in whatever format it is found. (There are no transform, encode or multiplex steps, because the output is only a fingerprint; not a media file.)

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Types Of Steganography

Steganography is derived from the Greek for covered writing and essentially means “to hide in plain sight”. As defined by Cachin steganography is the art and science of communicating in such a way that the presence of a message cannot be detected. Simple steganographic techniques have been in use for hundreds of years, but with the increasing use of files in an electronic format new techniques for information hiding have become possible. Steganography can be split into two types, these are Fragile and Robust. The following section describes the definition of these two different types of steganography.

1. Fragile

Fragile steganography involves embedding information into a file which is destroyed if the file is modified. This method is unsuitable for recording the copyright holder of the file since it can be so easily removed, but is useful in situations where it is important to prove that the file has not been tampered with, such as using a file as evidence in a court of law, since any tampering would have removed the watermark. Fragile steganography techniques tend to be easier to implement than robust methods.

2. Robust

Robust marking aims to embed information into a file which cannot easily be destroyed. Although no mark is truly indestructible, a system can be considered robust if the amount of changes required to remove the mark would render the file useless. Therefore the mark should be hidden in a part of the file where its removal would be easily perceived.

There are two main types of robust marking. Fingerprinting involves hiding a unique identifier for the customer who originally acquired the file and therefore is allowed to use it. Should the file be found in the possession of somebody else, the copyright owner can use the fingerprint to identify which customer violated the license agreement by distributing a copy of the file.

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