Technical data

97
• routers’ “receive” key and “sender” Tx key don't match.
• Different keys and key files may be used with different remote destinations.
• For maximum security, as shown in these examples, Telnet and SNMP access should be disabled and
Use the console port to view error messages and progress. If you see “Unknown protocol” errors, the PPP
CHAP used.
Sample Configuration
The sample configuration is the same as the one provided in the preceding PPP DES Encryption example, but
use the Diffie-Hellman encryption command instead of the PPP DES encryption commands.
Sample:
login admin
remote setEncryption DESE_1_KEY dh96.num SOHO
save
reboot
File Format for the Diffie-Hellman Number File
The file consists of 192 bytes, in binary format. There are two 96-byte numbers stored, with the most
significant byte in the first position. For example, the number 0x12345678 would appear
000000...0012345678.
The first 96 bytes form the modulus. In the equation x' = g^x mod n, n is the modulus. According to Diffie
and Hellman, the modulus should be prime, and (n-1)/2 should also be prime.
The second 96 bytes form the generator, or g in the above equation. The generator should be a primitive root
mod n.
The remaining pieces of the encryption key (x and y) are randomly generated at connection time, and will
change every time the device connects.
You should contact an encryption expert to obtain cryptographically sound generator and modulus pairs,
should you wish to change the default values.
Default Modulus
00000000: c9 b4 ed 33 ba 7f 00 9e - ce e0 83 5d a5 4c 19 25
00000010: e0 2d 99 44 e8 8d cd 16 - 02 0e 6c 26 6d 15 7c 95
00000020: 82 9a 8c 2b 19 d0 56 da - 9b 5b a9 cd cf fb 45 2b
00000030: c9 6a 3c 26 e5 b8 1a 25 - 07 b8 07 22 ed 15 8a 56
00000040: 8b f4 30 f2 28 fc 6b f1 - bf a4 3e 87 f0 be d6 1c
00000050: 33 92 b9 5e d1 b7 20 8c - 92 02 cb e5 26 45 02 1d
Default Generator
00000000: 90 f0 09 78 cc 23 79 a8 - 6c 23 a8 65 e0 dc 0f 6d
00000010: fb a7 26 e8 63 0a 21 67 - 5a f8 0f 59 84 09 5c da
00000020: ef af af fc d2 5f 83 e2 - a7 27 05 34 17 94 1a 4f
00000030: b2 87 76 97 e7 48 43 db - 62 29 70 9e 7f eb 2c 6e
00000040: 5d 25 1d a1 65 f0 b4 e6 - 47 4d 25 23 0b 20 b9 93
00000050: 27 f0 56 12 5a 97 f6 c5 - 31 b6 19 fc 67 22 93 f5