Well only two more really difficult parts are left to implement and a bunch of trivial stuff after that. If it had someone working on it 8+ hours a day it could probably be done in 3-5 months. If it was only for private messaging and not group communications or anonymous transactions and other fancy things it could be done in 1 month because it could use a simple PIR instead of a sophisticated EKS. If it used trusted blind mixing instead of trustless blind mixing it could probably be done in a little over a month. Using EKS allows it to scale to group communications while resisting social network analysis, and also allows it to be used for a lot more general purpose things than one to one messaging, including group messaging and blogs and possibly even basic hidden websites (like Freenet Freesites more than I2P or Tor hidden services) and small scale file sharing (documents and images, not movies and games). The main problem right now is getting 8 man hours a day on it for 3-5 months, the people making it are not being paid or planning to make money off it and they have already put thousands of hours into coding what is done already, I think they are burned out a bit and not having as much time to donate to coding as they did at first. Figuring out how to implement EKS is going to be the biggest time sink, implementing fairly advanced cryptographic systems is time consuming and delicate work and it could take 3 months of research to even understand a whitepaper well enough to attempt implementing it. Hopefully trustless blind mixing can borrow heavily from Zerocoin, even implementing one of the centralized blind mixing schemes could take nearly a month. So for 1:1 messaging it could be done in a month with 8+ hours a day spent on it, for 1:1 messaging + Centralized Blind Bitcoin Mixing maybe two months, for 1:1 messaging + Trustless Blind Bitcoin Mixing 2-3 months depending on how easy it is to use the existing Zerocoin code for it or to base a similar system off the existing Zerocoin code and research, for a true "blind market" I wouldn't guess it would be done any sooner than 3 months but think it could be done by 5. It already has about 12 months of coding into it at about 8 hours a day. These are just rough figures as well it is really hard to estimate how long it will take to implement a given component. Implementing the anonymous routing algorithm for the mix network took several months by itself though and I don't think EKS looks any easier and actually it is probably harder but some of the components for it are already in available libraries, and there is already a really rough implementation available that can work as a frame work.