Can It Play Mp3-files In Energy-saving Mode?


Chip said:
<-snip->
Having an open source DRM scheme is sort of like writing the combination to a safe on the safe.
But aren't there several open source encryption systems? They serve a similar purpose (protect data) and they're not trivial to crack just because they're open source... right?
 
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Nilsiboy said:
Chip said:
Having an open source DRM scheme is sort of like writing the combination to a safe on the safe.
But aren't there several open source encryption systems? They serve a similar purpose (protect data) and they're not trivial to crack just because they're open source... right?
A DRM scheme relies on "security by obscurity", in contrast with the traditional open source approach of "many eyes see many flaws". If it would be open source not only would an attacker have all the information he needs (with the possible exception of encryption keys), but he could simply recompile the program without the DRM. It's theoretically possible to make part of the application open source, but not the DRM part.
 
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QUOTE
Having an open source DRM scheme is sort of like writing the combination to a safe on the safe.


Bad analogy. That's like saying the DRM source code would contain every possible decryption key. I do see where your coming from however, as in, files you can play you could convert to other non-DRM formats. However, you can do that with a lot of DRM'd content anyway :D

Also, whats the point of recompiling a program without DRM? Most software can play non-DRM'd files anyway? Maybe I should read up...
 
Squidge said:
Also, whats the point of recompiling a program without DRM? Most software can play non-DRM'd files anyway? Maybe I should read up...
Some software that downloads stuff first get things through SSL or some other encrypted medium and then apply DRM with keys specific to the user.
DRM is just a bad idea anyway, so it's a bit pointless to discuss it.
 
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MWeston said:
What I thought would be ideal is to suspend Linux to SDRAM and then put the external memory to sleep. Then, using the internal scratch pad RAM, and maybe using the DSP core and its RAM, a low power, low speed music player could be run to just play music and use the shoulder buttons to change tracks.
When you say scratchpad RAM are you referring to locked down L2 cache, or is there some kind of specific scratchpad in addition to the 16/16/256 L1/L2 we know of? (not counting the DSP's of course)

EDIT: I see there's 64KB of shared SRAM at 0x40200000, that's probably what you meant. I wonder how fast it is...
 
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Squidge said:
QUOTE
Having an open source DRM scheme is sort of like writing the combination to a safe on the safe.
Bad analogy. That's like saying the DRM source code would contain every possible decryption key. I do see where your coming from however, as in, files you can play you could convert to other non-DRM formats. However, you can do that with a lot of DRM'd content anyway :D



OK, the analogy isn't 100% accurate, but the basic concept is sound. Lets say MS made Window Media Player 11 open source. Somebody with even a tiny bit of programming skill could go into the code, find the part that phones home to check if a DRMed track is authorized, and change it to authorize everything without actually checking.

How's this for a better analogy: It's like having a solid steel door on your bank vault with unpickable locks and armed guards, but if you walk around the back of the building, there's an unlocked screen door that goes right into the same vault.

Squidge said:
Also, whats the point of recompiling a program without DRM? Most software can play non-DRM'd files anyway? Maybe I should read up...

As you can see, the point is not to recompile without DRM, it is to recompile with the 'M' part of 'DRM' disabled :D
 
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Chip said:
OK, the analogy isn't 100% accurate, but the basic concept is sound. Lets say MS made Window Media Player 11 open source. Somebody with even a tiny bit of programming skill could go into the code, find the part that phones home to check if a DRMed track is authorized, and change it to authorize everything without actually checking.
It would be great if that was how it worked. Even with closed source, someone would eventually patch the application.

In reality, most DRM works by "phoning home" and asking for a license or decryption key to play the content. The key is forgotten once you close the player and has to be re-fetched each time (and sometimes the key is dependant on a random key based on time, so you can't use the same key a week later). So if the media you are playing has timed out (eg. you have a license to play it only for 24 hours), then no amount of source code hacking is going to be able to play that file. You must patch the program whilst you have authorisation to view the file.

So, going back to your bank analogy, you can only raid the vault whilst you have the combination - if the combination changes and no one will give you the new one, getting in will be very difficult.
 
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