I am looking into the GMSS - Generalized Merkle Signature Scheme.
There is an implementation in the BouncyCastle Libs and in FlexiProvider
http://www.flexiprovider.de/. Both very similar / the same.
I am using the FlexiProvider implementation and hacking my own version that can be initiated with a seed.
It seems that your Private key changes after every time you use it. The Public key stays the same. You have to do this for security reasons.
What I am wondering is how to jump to the correct private key after you have turned the machine off/on..?
I do not want to have to save the key, as everything must be re-settable from your 'seed key' and the number of previous signings..
What i mean is that currently, and looking through the code, the only way is to run next() on the private key until you reach the key you are currently on. (This effectively traverses a merkle tree of hashes creating your new private key) If you use the key 1000 times, you'll need to use next() 1000 times. Takes about 10s for 1000 on my mac book air...
Is it possible to jump to the ACTUAL key, say 1000 in, in one go ? (I'm not sure as the construction of the key 'may' require the incremental hash of the tree..)
Does anyone know if this is possible ?
