Is it possible to retrieve data covered with a black box?

[costinb68982656]

Hello,

I have a scanned pdf doc. I opened it in PS to cover some sensitive info. I draw some black boxes over the text. Then I merged all the layers, icluding original layer. I had only one layer in the end and save it as pdf. There was no way to be able to recover the hidden text. I sent the file to someone and somehow he asked me about something that was hidden under the black boxes. 

I tried to open the pdf with PS, Ilustrator and Acrobat Pro but no way I can see what's under the black boxes.

My question is.... Is there a work around to retrieve those hidden info despite the fact that all the layers was merged in one?

[Ged_Traynor]

Hi

Once you merged the layers, saved and closed the file you're out of luck, unless you have a backup copy

[c.pfaffenbichler]

Photoshop offers Layers and Alpha Channels but for a flat image without additional Channels there are no pixels hiding behind the pixels. 

If the black box was not in fact solid (either because of Opacity below 100% or because it was a dark gray set to Blend Mode »Multiply« or …) it could be possible that there is some information left but as you saved a pdf even that would probably be degraded by the jpg-compression.