- For an RSA signature scheme, I provide the public key (n,e), where
137
n=2 -1, e=17
- This value n has two large prime factors.
Use my public key to verify my signature of the following message:
This is my text.
68767027465671577191073128495082795700768
- Now try with the public key
67
n=(6 - 1)/5, e=17
- to verify my signature:
Please feed my dog!
1703215098456351993605104919259566435843590978852633
- For a Rabin signature scheme, I provide the public key
74
N=(7 -1)/6,
which I know can be factorized into two large primes.
- Check the following message and signature:
Arrive Thursday.
189479723122534414019783447271411895509
- For an El Gamal signature scheme, I choose the next prime after
150
2
which has a primitive root a=2. My public key is
B=1369851585774063312693119161120024351761244461
- Verify the signature
Leave AT ONCE!,
1389080525305754392111976715361069425353578198
1141326468070168229982976133801721430306004477
- For a DSS signature, choose p to be the next prime after
170
2 and q=143441505468590696209
- Verify that q is a divisor of p-1.
A primitive root of p is a=3.
Use this primitive root to determine
(p-1)/q
g = a mod p
- The public key value is
B=1394256880659595564848116770226045673904445792389839.
- Now using these values, verify this signature:
Now's your chance!
64609209464638355801
13824808741200493330
- Now exchange some public keys with a friend, and sign messages to each
other. Then verify the signatures you have been sent. Make sure you try
each of
- RSA signatures,
- Rabin signatures,
- El Gamal signatures,
- DSS.