SOLVED. Adult SciFi: Physicist, quantum computing, cryptography, alien contact. [s]

[Steven]

The book involves a physicist involved in quantum computing and cryptography. He comes to believe that he is receiving messages from aliens. The intentions of the aliens toward humanity is not clear. There is a national security or law enforcement element as well. Read this some time between 2000-2010.

[Ingo]

Sounds to me a lot like:
Signal to Noise
and the sequel:
A Signal Shattered
both by Eric S. Nylund Eric S. Nylund

This may not available new, and also there is no ebook available (yet). I wrote to the author regarding that, as I want to read both again, and will gladly pay for them again.

Even if this is not your searched for book:
I highly recommend these 2 books.
One of my favourite aliens "Wheeler".

[Steven]

That's it! Thank you so much!