[Cryptography] Some questions for a course

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> Does anyone have a cost for breaking 512 bit DH on Amazon compute cloud or
> similar (order of magnitude would be fine) ?
> And same for Logjam type attack on the prime.

https://weakdh.org/imperfect-forward-secrecy-ccs15.pdf

For purposes of comparison, a single 512-bit RSA factor-
ization using the CADO-NFS implementation takes about
eight days of wall-clock time on the computer used for the
descent, and about three hours parallelized across 1,800 cores
of Amazon EC2 c4.8xlarge instance


> Also source for Work Factor or RSA2048, I am pretty sure it is 112 but my
> Google karma has deserted me.

http://web.archive.org/web/20131112190634/http://www.nsa.gov/business/programs/elliptic_curve.shtml

Symmetric RSA/Diffie-Hellman	Elliptic
80 	1024 	160
112 	2048 	224
128 	3072 	256
192 	7680 	384
256 	15360 	521
Table 1: NIST Recommended Key Sizes