A Digital Signature Algorithm Example

Math 202 Cryptography, November 16, 2016
T. Ratliff, Wheaton College
ratliff_thomas@wheatoncollege.edu

Key Generation

p=
q=1331985975749110751467452671644594430583873510479
α = 
d=178482584654999441663585665066279244253783610235

Use the commands PrimeQ[p] and IntegerLength[p,2] to verify that p is prime and of the correct size. Do the same for q.

Verify that α has order q in (SuperStar[(Subscript[Z, p])])

Compute β

Sign the message

x="You keep using that word,I do not think it means what you think it means."
kE = 758579245332948359575909007264541594859712766065

Determine the signature (r,s).
You will need to find ((Subscript[k, E])^(-1)) mod q and use the command Hash[x, “SHA”]

Verify the signature