Hi all! I have a question regarding this recent commit to the linux kernel:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/char/random.c?id=6e9fa2c8a630e6d0882828012431038abce285b9 It is referencing this paper: http://eprint.iacr.org/2012/251.pdf I played around with the new/fixed polynomial in sage a bit but could find this polynomial to always be reduceable: === sage: F = GF(2, 'c') sage: F.<t> = PolynomialRing(F, 't') sage: P = t^128 + t^104 + t^76 + t^51 + t^25 + t + 1 sage: Q = t^32+t^26+t^23+t^22+t^16+t^12+t^11+t^10+t^8+t^7+t^5+t^4+t^2+t+1 sage: Z = Q^3 * (P - 1) + 1 sage: Z.is_irreducible() False === sage: F = GF(2^32, 'c') sage: F.<t> = PolynomialRing(F, 't') sage: P = t^128 + t^104 + t^76 + t^51 + t^25 + t + 1 sage: Q = t^32+t^26+t^23+t^22+t^16+t^12+t^11+t^10+t^8+t^7+t^5+t^4+t^2+t+1 sage: Z = Q^3 * (P - 1) + 1 sage: Z.is_irreducible() False === sage: F = GF(2^32, 'c') sage: F.<t> = PolynomialRing(F, 't') sage: P = t^128 + t^104 + t^76 + t^51 + t^25 + t + 1 sage: Q = t^32+t^26+t^23+t^22+t^16+t^12+t^11+t^10+t^8+t^7+t^5+t^4+t^2+t+1 sage: Z = (Q^3).substitute({t:P - 1}) + 1 sage: Z.is_irreducible() False === ... What am I missing? I guess I have misunderstood something. Thanks, Hannes _______________________________________________ RNG mailing list [email protected] http://lists.bitrot.info/mailman/listinfo/rng
