What would stop someone from getting the chunks before they are dispersed on the network? Could someone get the chunks and putting the file back together?
The file is encrypted using self-encryption. So only the owner with the right private key can unlock what’s inside the file.
I’m no crytography expert, but my understanding is that the more encrypted data you can acquire, the more “clues” you get in order to crack the encryption key (that’s how the British cracked Enigma in WW2). So I believe the keys will have to be changed regularly, similar to how an IPSEC VPN does that.
It was a different kind of encryption back then, since the 1970’s new and better encryption techniques have been discovered (prime factorization, discrete logarithms, eliptic curve cryptography). As far as I know decrypting does not get easier as you get more encrypted data with these new techniques.
There is no ‘getting closer’ anymore, you either have the key and can decrypt everything, or you don’t and all you get is completely random data.
Perhaps it’s proper to call the old techniques enciphering/deciphering and the new techniques encrypting/decrypting?
Every chunk is always encrypted with a new private key, that is generated with hash of other data chunks. These private keys are automatically stored in data maps that themselves are encrypted this way. The private key that unlocks the root of this data map tree is generated from your private password. Thanks to self-authentication, this password is never sent out over the network. So in conclusion, no private keys are ever used more than once.
So strictly speaking, you generally do get more information as you encrypt more data. But with modern cryptography, the gain is so minuscule that even the best known attacks need so many as to make it almost as impractical as a brute-force attack.
Is hash of the current chunk also included in key generation for encrypting that chunk, or is it just other chunks?
only the hash of other chunks.