Re: RSA question as well, following B. Schneier book example

Mike Amling a écrit :

They do not have the same lenght. Is this normal?

Yes, this is normal. The ciphertexts should all be in the range 0..3336, and they are. No one ever claimed they'd have the same number of decimal digits as each other or as their plaintexts, when you omit leading zeros.


--Mike Amling

Thank you all for your answers.

Carlos Moreno was right, it was 17, not 7, my mistake.


Regarding the lenght of cyphered message blocs, i cannot just put them together and send them, as the receiver Alice will not be able the know which size is each bloc.

If i understand you, i have to fill with leading zero's ? in this case, is this last column ok?

+---+-------------------+------+--------+
| m | (m^3) mod 3337 | c | sent c |
+---+-------------------+------+--------+
|284| 284 3 ^ 3337 % p | 1136 | 1136 |
|832| 832 3 ^ 3337 % p | 875 | 0875 |
|595| 595 3 ^ 3337 % p | 87 | 0087 |
|625| 625 3 ^ 3337 % p | 2368 | 2368 |
|120| 120 3 ^ 3337 % p | 2771 | 2771 |
|282| 282 3 ^ 3337 % p | 1128 | 1128 |
+---+-------------------+------+--------+

So the final message will be :

C = 113608750087236827711128


--
Vincent Badier
.