Fixed ElGamal prime URL + added prime to the text.

www.i2p2/pages/how_cryptography.html

@@ -17,8 +17,8 @@ technique used in <a href="how_elgamalaes">ElGamal/AES+SessionTag</a> (but we're
 <H2><a name="elgamal">ElGamal encryption</a></H2>
 
 <p>
-We use common primes for 2048 ElGamal encryption and decryption, and we currently only
-use ElGamal to encrypt the IV and session key in a single block, followed by the 
+We use common primes for 2048 ElGamal encryption and decryption, as given by <a href="http://tools.ietf.org/html/rfc3526">IETF RFC-3526</a>.
+We currently only use ElGamal to encrypt the IV and session key in a single block, followed by the 
 AES encrypted payload using that key and IV.  Specifically, the unencrypted ElGamal 
 block is formatted (in network byte order):
 <p>
@@ -43,10 +43,24 @@ ElGamal is never used on its own in I2P, but instead always as part of
 <p>
 The shared prime is the 
 
-<a href="http://www.ietf.org/proceedings/03mar/I-D/draft-ietf-ipsec-ike-modp-groups-05.txt">[Oakley prime for 2048bit keys]</a>
+<a href="http://tools.ietf.org/html/rfc3526#section-3">[Oakley prime for 2048bit keys]</a>
 <PRE>
  2^2048 - 2^1984 - 1 + 2^64 * { [2^1918 pi] + 124476 }
 </PRE>
+or as a hexadecimal value:
+<PRE>
+ FFFFFFFF FFFFFFFF C90FDAA2 2168C234 C4C6628B 80DC1CD1
+ 29024E08 8A67CC74 020BBEA6 3B139B22 514A0879 8E3404DD
+ EF9519B3 CD3A431B 302B0A6D F25F1437 4FE1356D 6D51C245
+ E485B576 625E7EC6 F44C42E9 A637ED6B 0BFF5CB6 F406B7ED
+ EE386BFB 5A899FA5 AE9F2411 7C4B1FE6 49286651 ECE45B3D
+ C2007CB8 A163BF05 98DA4836 1C55D39A 69163FA8 FD24CF5F
+ 83655D23 DCA3AD96 1C62F356 208552BB 9ED52907 7096966D
+ 670C354E 4ABC9804 F1746C08 CA18217C 32905E46 2E36CE3B
+ E39E772C 180E8603 9B2783A2 EC07A28F B5C55DF0 6F4C52C9
+ DE2BCBF6 95581718 3995497C EA956AE5 15D22618 98FA0510
+ 15728E5A 8AACAA68 FFFFFFFF FFFFFFFF
+</PRE>
 <p>
 Using 2 as the generator.
 <p>