A Proposal for an ISO Standard for Public Key Encryption (version 2.0) Victor Shoup IBM Zurich Research Lab, S¨aumerstr.4, 8803 R¨uschlikon,Switzerland
[email protected] September 17, 2001 Abstract This document should be viewed less as a first draft of a standard for public-key encryption, and more as a proposal for what such a draft standard should contain. It is hoped that this proposal will serve as a basis for discussion, from which a consensus for a standard may be formed. Summary of Changes from version 1.1 (February 13, 2001) to ver- sion 2.0 (September 17, 2001) Some new and quite severe criticisms of the security of ECIES in certain modes of operation • have been added. Specifically, it is shown that in certain modes of operation, the scheme is malleable in a very strong and quite non-trivial sense. See 15 and in particular 15.6.4. x x The implementation of \cofactor mode" for ECIES is now based on the notion of \compatible • cofactor mode" in IEEE P1363a, and the \old cofactor mode" is no longer recommended. See 15 as well as 15.6.5. x x A new \primitive" called a data encapsulation mechanism has been introduced (see 4). This • primitive was implicit in previous versions, but now it has been made explicit. Thisx is mainly just a conceptual change. Note, however, that there is one slight change in the recommended implementation of the primitive (which we call DEM1); namely, the way in which the length of the label is formatted when passed to the MAC.