It's great to see that someone is trying to establish standards in bitcoin community. A while ago I was doing a bit of research regarding the private key export and came to a conclusion that OpenPGP message format would suit this use case perfectly. I encourage you to take look into
RFC 4880 if you haven't already, quite a brilliant piece of work. What I advocate is to use the existing, vast system that OpenPGP is and try fitting bitcoin into it.
Advantages to taking this approach are numerous.
- OpenPGP is a well known and tested standard
- Security is built in
- There is room for growth and modifications
- It's very robust and covers almost all use cases
- Possible use of existing OpenPGP compliant architecture
There is one great disadvantage, though. With robustness comes complexity - it's not a quick and easy fix to the problem of key sharing but rather a lengthy process of integrating bitcoin into OpenPGP ecosystem.
This sounds very interesting. I can see simple use cases like using one EC key both as a bitcoin account and for signing PGP messages. Possibly using a bitcoin-disclosed public key to encrypt messages, if this is safe. How else would integration be possible?
Another factor, GnuPG has yet to produce a stable release with support for EC keys.