These three stream ciphers were chosen for the final hardware profile of the eSTREAM portfolio. As far as I understand it, their merits are:
- Trivium: elegant design, very high throughput per area, small area, parallelizable.
- Grain: simple design, small area, high throughput, comes in a 128 bits flavor and in an authenticated version, easy area-throughput tradeoff.
- MICKEY: small area.
(source: http://asic.ethz.ch/estream)
As I see it, Trivium and Grain have many more strengths than MICKEY. So my question is:
Are there qualitative (e.g. a property like Trivium's parallelazibility) or quantitative reasons that would make MICKEY a better choice than the two other ones in some situations?