What are the advantages of MICKEY over Trivium and Grain?

Question

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?

Answer 1

MICKEY appears to be a good low-power stream cipher but, in the context of the eSTREAM portfolio, it does not seem to excel at anything in particular. Trivium and Grain have more implementation flexibility and lower area, if one wishes, and Trivium also allows for fast bitsliced software implementations that rival the software eSTREAM candidates in speed.

The one thing MICKEY appears to be better at than others is simplicity (in number of VHDL code lines), as seen in Table 8 of Chapter 19 of the eSTREAM book. This does not strike me as a particularly strong argument for it, since the line numbers between the best entries are all fairly close together.

MICKEY also appears more conservative when it comes to security; in particular, Trivium and Grain have been targets of more algebraic-type cryptanalysis. But this is something that is hard to quantify, and may be mainly a consequence of Trivium/Grain being more popular than MICKEY.