Can cryptonote be implemented into Bitcoin?

[Patel]

Hey everyone,

Fishing for opinions if it is possible to implement cryptonote into Bitcoin to provide a solution for privacy/anonymity, for the bitcoin currency rather than using altcoins such as XMR/BCN.

Protocol: Adding a new address type or implementing ring signatures to Bitcoin. Is it possible? What kind of work is involved?

Sidechains: Not much information on sidechains yet, but about 2-3 months ago, I believe the rumor was in 60-90 days they would share more info. Does anyone know if Monero can be added into a Bitcoin sidechain?

[rapport]

related https://bitcointalk.org/index.php?topic=702584.0

as for sidechains / Blockstream, they seem to be pretty quiet and secretive and haven't released much info apart from the concept