arndt@ttds.UUCP (Arndt Jonasson) (11/01/85)
The following hex dump (produced with od -x) is a text encrypted with
a stream cipher, using pseudo-random numbers. If you feel like testing
your cryptographic knowledge on this puzzle, you are invited to try to
crack the cipher.
This is not an attempt to make you inadvertently help us cracking into
something secret. It is a serious attempt to test an algorithm.
Comments and (hopefully not) reports of success should be directed to:
{ucbvax, philabs}!mcvax!enea!ttds!arndt
9dae 8136 4712 bef3 47a4 2668 ca00 f993
0e29 0636 89b8 2a16 e91e 1324 91bc 29dd
f69a 2e91 d224 0939 2a1a 3a23 5a22 d215
c9be 8476 1ca3 e4ec d745 043c 0d1f c4a9
1917 12c6 a252 ed16 f14e d131 6ce8 ff3f
cc58 fc59 5c32 de88 bd1f 4311 864c 7386
8ba1 0d6e 8758 fc63 b546 e331 f1cb 1802
14ac c302 0fb7 e454 d142 1e6a dc54 8aa8
5640 a3de cf52 0195 afac 1c98 f742 08fb
422d ffe7 bb22 b574 01ca c21f ebf2 0346
15a7 88e2 83e8 ee3b 341d 2b81 6af5 273f
da5d 5caa d7f4 503a dd3a 34b5 eea2 eea9
650d f0af d05d 3827 0fc7 568e 8f94 c722
179e 9609 468f 4edf 49cf f28b 4bf7 11db
6e65 4203 7c7c d232 635a 58fb 4015 b32c
2fb8 4387 dbc4 b156 02f5 d929 9ea9 ec25
4f33 7375 b638 461a 29d3 4766 c638 ccec
baed fa87 5a75 faeb 2f62 ddde b7d9 f9f6
dcbb a110 3ca5 509a 123f bc6b 23b0 30a4
3c66 f5c4 dcc0 a8e3 72eb fa51 28f5 d9c2
1ec5 986d b229 263f 5cb0 ae86 0813 c92e
0b7e 9df4 f41c 9d33 7f78 e609 a7db 38b4
d644 c50b dd78 8259 9fe2 1660 49a5 b2ef
9ecc 9807 dbf9 fb4a 35d8 635a 0372 18ce
48df 3104 cc84 23fc 6d94 fb09 1bf9 c71f
78ce 2880 595c 32a7 f5f5 827a d18c b343
1718 64d1 e423 db76 43ee 0a3d fb69 bd28
16dc 9031 bf34 0cdf fc08 c096 c45a 1af3
1382 06fc e691 2f40 4f42 58ad 8c4d 6082
49e9 0473 bc95 2877 f3de bf87 aa0f e82d
1c06 79cc 0413 af87 c75e ec5c 1acb e49f
f2cd 57ad 8330 99fe b92b 7d0b 157a 279d
989f 93d9 a75b 9b04 1ab0 933b d2e6 3af2
55ec 7a0e 10aa 8c28 3f94 4bb6 e09b 72cc
c614 f007 115f 0bf5 e878 aca4 7e83 5cbd
39b2 0dc5 5efe 2f33 eac0 a19e 249c 1fd9
e923 2f10 ec4e c7fd 9a8a 48c9 b0ca f4c3
97a5 de94 2f9d e204 7fe4 d704 1d95 f631
7b5d c253 fc7a d3be 03b7 ef8c 1dc5 d250
e3f3 1069 2a08 25a3 eff1 816b a4c2 a832
8a00
Arndt Jonasson, Tommy Bohlin
ZYX Research, Stockholm
[uucp address above]
Subject: Crypto puzzle.
Newsgroups: net.crypt, net.puzzle
The following hex dump (produced with od -x) is a text encrypted with
a stream cipher, using pseudo-random numbers. If you feel like testing
your cryptographic knowledge on this puzzle, you are invited to try to
crack the cipher.
This is not an attempt to make you inadvertently help us cracking into
something secret. It is a serious attempt to test an algorithm.
Comments and (hopefully not) reports of success should be directed to:
{ucbvax, philabs}!mcvax!enea!ttds!arndt
9dae 8136 4712 bef3 47a4 2668 ca00 f993
0e29 0636 89b8 2a16 e91e 1324 91bc 29dd
f69a 2e91 d224 0939 2a1a 3a23 5a22 d215
c9be 8476 1ca3 e4ec d745 043c 0d1f c4a9
1917 12c6 a252 ed16 f14e d131 6ce8 ff3f
cc58 fc59 5c32 de88 bd1f 4311 864c 7386
8ba1 0d6e 8758 fc63 b546 e331 f1cb 1802
14ac c302 0fb7 e454 d142 1e6a dc54 8aa8
5640 a3de cf52 0195 afac 1c98 f742 08fb
422d ffe7 bb22 b574 01ca c21f ebf2 0346
15a7 88e2 83e8 ee3b 341d 2b81 6af5 273f
da5d 5caa d7f4 503a dd3a 34b5 eea2 eea9
650d f0af d05d 3827 0fc7 568e 8f94 c722
179e 9609 468f 4edf 49cf f28b 4bf7 11db
6e65 4203 7c7c d232 635a 58fb 4015 b32c
2fb8 4387 dbc4 b156 02f5 d929 9ea9 ec25
4f33 7375 b638 461a 29d3 4766 c638 ccec
baed fa87 5a75 faeb 2f62 ddde b7d9 f9f6
dcbb a110 3ca5 509a 123f bc6b 23b0 30a4
3c66 f5c4 dcc0 a8e3 72eb fa51 28f5 d9c2
1ec5 986d b229 263f 5cb0 ae86 0813 c92e
0b7e 9df4 f41c 9d33 7f78 e609 a7db 38b4
d644 c50b dd78 8259 9fe2 1660 49a5 b2ef
9ecc 9807 dbf9 fb4a 35d8 635a 0372 18ce
48df 3104 cc84 23fc 6d94 fb09 1bf9 c71f
78ce 2880 595c 32a7 f5f5 827a d18c b343
1718 64d1 e423 db76 43ee 0a3d fb69 bd28
16dc 9031 bf34 0cdf fc08 c096 c45a 1af3
1382 06fc e691 2f40 4f42 58ad 8c4d 6082
49e9 0473 bc95 2877 f3de bf87 aa0f e82d
1c06 79cc 0413 af87 c75e ec5c 1acb e49f
f2cd 57ad 8330 99fe b92b 7d0b 157a 279d
989f 93d9 a75b 9b04 1ab0 933b d2e6 3af2
55ec 7a0e 10aa 8c28 3f94 4bb6 e09b 72cc
c614 f007 115f 0bf5 e878 aca4 7e83 5cbd
39b2 0dc5 5efe 2f33 eac0 a19e 249c 1fd9
e923 2f10 ec4e c7fd 9a8a 48c9 b0ca f4c3
97a5 de94 2f9d e204 7fe4 d704 1d95 f631
7b5d c253 fc7a d3be 03b7 ef8c 1dc5 d250
e3f3 1069 2a08 25a3 eff1 816b a4c2 a832
8a00
Arndt Jonasson, Tommy Bohlin
ZYX Research, Stockholm
[uucp address above]arndt@ttds.UUCP (Arndt Jonasson) (11/01/85)
Due to a mistake, the text in my previous article was duplicated. I apologize.
gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) (11/03/85)
A much better test would be to include a complete description of the encryption system, omitting only the particular keys used (and the plaintext, of course). In practice, this information will become available to the cryptanalyst one way or another. Most professional cryptanalysts are not especially interested in solving challenge cryptograms, for the same reason that most mathematicians don't bother with proofs of Fermat's last theorem sent to them and that most physicists don't check out unsolicited theories of the universe that arrive in the mail. This may be a good cryptosystem or it may not, but if it takes much effort to crack, people are only going to attempt it if they have sufficient motivation. Suppose for example that someone discovers a weakness that allows him to unravel the message, and that he reports that to you. Would you at that point give up? No, much more likely you'd modify your encryption scheme slightly to plug that particular loophole. The analyst would then have to start over, find the next loophole (there is almost certain to be one), inform you of that, and watch as you fail to get the idea and instead apply yet another patch. One way to really subject your scheme to a good test would be to publish a description of the workings of the cryptosystem along with a very large continuous sample of encrypted text, and to offer a substantial monetary reward for the first person who can mail you a prespecified length of decrypted text, enough to compensate for the hours of hard work that may be involved. Of course, if it is really not a very good cryptosystem, some hacker may break it just from what you posted, but failure to have it broken that way will not prove anything about its security against a determined attack by experts. I hope these suggestions will be taken in the constructive spirit in which they are offered.