Monitor radiation overlooking.
Hello! I read about overlooking of monitor radiation. Introder can scan the electron-beam radiation from electron-gun. He simple transmit this radiation to self electron-gun and sinchronize frequance. This method work with b/w monitor. The overlooking of color-monitor more dificult - introder will see 4 gradation of gray (all guns off, work one, two, three guns). But we can select spesial colors (red-blue or blue-green) and allways will work only one (or two) guns. In this way introder will see dark (or light) gray screen without any information!!! Is it corect? Do now present more improve overlooking system? Some words about DES - I spoke with one cryptoanalisyst from KGB and he sow, that for number crypto algotitm c(key, text) (key is keyLength tall) present f(key, text), that for all key1 and key2 present key with length keyLength, that c(key2, c(key1, text))==f(key, text). He also say, that now present f() for c()=des(), more f() wery like des(). That`s why for decrypting of des(k1, des(k2, ... des(kN, text) ... )) we must try 2^56 keys with spetial function. --- Victor A. Borisov aka blaster; Relcom R&D; Email: blaster@rd.relcom.msk.su; Phone: +7(095)-943-4735; +7(095)-198-9510; === Don`t panic! ===
Excerpts from internet.cypherpunks: 15-Oct-93 Monitor radiation overlooking. Victor A. Borisov@rd.rel (1286)
Some words about DES - I spoke with one cryptoanalisyst from KGB and he sow, that for number crypto algotitm c(key, text) (key is keyLength tall) present f(key, text), that for all key1 and key2 present key with length keyLength, that c(key2, c(key1, text))==f(key, text).
He also say, that now present f() for c()=des(), more f() wery like des().
That`s why for decrypting of des(k1, des(k2, ... des(kN, text) ... )) we must try 2^56 keys with spetial function.
I had a little trouble with the English, but I think I followed the math. I believe Victor's KGB friend is claiming that DES is a group. Victor, does the following text contradict your claim?
From the Crypto FAQ: Excerpts from netnews.sci.crypt: 4-Oct-93 Cryptography FAQ (05/10: Pr.. crypt-comments@math.ncsu (20767)
The security of multiple encipherment also depends on the group-theoretic properties of a cipher. Multiple encipherment is an extension over single encipherment if for keys K1, K2 there does not exist a third key K3 such that
E_K2(E_K1(X)) == E_(K3)(X) (**)
which indicates that encrypting twice with two independent keys K1, K2 is equal to a single encryption under the third key K3. If for every K1, K2 there exists a K3 such that eq. (**) is true then we say that E is a group.
This question of whether DES is a group under this definition was extensively studied by Sherman, Kaliski, and Rivest [SHE88]. In their paper they give strong evidence for the hypothesis that DES is not a group. In fact DES is not a group [CAM93].
[CAM93] K. W. Campbell, M. J. Wiener, Proof the DES is Not a Group. In Proceedings of CRYPTO '92, 1993.
[SHE88] B. Kaliski, R. Rivest, A. Sherman, Is the Data Encryption Standard a Group. Journal of Cryptology, vol. 1, #1, 1--36, 1988.
I had a little trouble with the English, but I think I followed the math. I believe Victor's KGB friend is claiming that DES is a group. Victor, does the following text contradict your claim? Sorry for my poor English. I want to saw, that DES is`t group. We can`t say,
that: A k1, k2: E k0, that des(k2, des(k1, text))=des(k0, text) (A mean "for all", E mean "exist"); or: E k1, k2: A k0, that des(k2, des(k1, text))!=des(k0, text) I saw, that: E f(k, text): A k1, k2: E k0, len(k0)=len(k1)=len(k2), that des(k2, des(k1, test))=f(k0, text) f() like des(), but f() is not des()!!! My friend saw, that introder must try only 2^56 keys for des(des()). Once more, sorry for my poor English. PS I am sorry for my stupid letter about PGP randomizer. --- Victor A. Borisov aka blaster; Relcom R&D; Email: blaster@rd.relcom.msk.su; Phone: +7(095)-943-4735; +7(095)-198-9510; === Don`t panic! ===
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blaster＠rd.relcom.msk.su -
Lyle_Seaman＠transarc.com