We are implementing searchable encryption techniques proposed by Song et al in Java for a paper. The schemes need a Stream Cipher for achieving search over encrypted data. The stream of random bits should be reproducible later while decryption given the same "Seed".
Now we plan to generate the stream of random bits using AES in CTR mode. What we don't understand is what is considered as "seed". Is "seed" the random 64 bits prefix part of the IV / Nonce ?
What would be the plain text CTR mode while generating random stream ? Can we give some hard coded string as plain text as we don't really care what we are encrypting, all we want is random stream of bits that could be reproduced later
Or what is considered a secure way to generate random stream of bits ?
 Song, Dawn Xiaoding, David Wagner, and Adrian Perrig. "Practical techniques for searches on encrypted data." Security and Privacy, 2000. S&P 2000. Proceedings. 2000 IEEE Symposium on. IEEE, 2000.