The W3C WebCrypto working group recently made an inquiry to the IETF JOSE working group about the possibility of defining a JSON representation for private keys. To facilitate discussion of this topic by both working groups, I created a draft JSON Private Key specification. The specification is very simple; it just defines two additional members for the JWK structure for representing the private parts of Elliptic Curve and RSA keys.
The specification is available at:
A HTML-formatted version of the specification is available at: