Math 348 (Cryptography)

Prof. Weibel

Spring 2004
Homework Assignments
All assignments are due on Tuesdays.
Go to the current assignment
Due dateSection/Problems Section/Problems
1/27/04 (Tues)Encrypt: your name in Caesar (k=13); 'cryptography' with k=1st letter of your last name 1.1#6,14; 1.2#13,18; 1.3#1; 1.4#1,6,9,12,19
2/3Cryptoquote: IDIED IVJIE DJUUJ TGEIT JHAPG SJEEJ QUJPI JOXJT GOTSJ EEGLS JVGOR - LN EXADD JSSJTWJ 2.3 #1,2; 2.4 #1,3 (affine);
3.1 #3,4
2/10Jumbles ZEROF, FLOWEL, TYMIA, HYNWIN
SSA PSE TJX SME CRE STO THI GEI (padded)		 3.2 #7,9; 3.3 #4,7,11;
3.4 #1,2,9,10; 3.5 #1,3
2/17Decrypt the "VIGNERE TEXT" below using a Kasiski attack 4.1 #2,7,8,9; 4.3 #1,4,10
VIGENERE TEXT (330 characters)
PHCYE LXELD QFELC RSNTS ASOIM EPPRK AEZFW CWILR IJXDU LGKAE
DZFDX RRLJV KNQTU EHFRS SIXDJ TCEPH CCSKA EHLBU CBSTZ UBNET
GEHWG XOXBN CEFPB NEECC XAPYO SHURL FZMHK PHZVA LOUIX EIHVZ
EEQXS CEILR GLWSB FFZGG RSSIX VMWIK BOLLF PPAPE VVVLY DGVLW
CCSYX LBTBS TRLDW EUERH SVGSI TFDBS FPGNB TFEVV URGEW JAADE
SIMHC HOIMH CNCCE EEPFV LUKPR DXERT BXTTR SSJBG LZTKA EPPRC
BOLFB KBLKZ JZGGR ZAFGU KPBKL QSLFV
2/24Friedman attack on the "VIGENERE TEXT" above 4.4 #5,10; 4.5 #1,2
3/2Knowntext attacks: Find 1) key for Hill Cipher with B=3, e(DAABBACDB)=(DUDDABIFK), and
2) key for Affine Hill cipher B=2, e(GA HF BC)=(YJ BC JB)		8.1 #1,2 and decrypt Hill cipher HBBBABSBIIHI with B=2,
probable word 'BEARS'
3/9Find (x+1)-1 and (x2+1)-1 in F4, F8 (see 26.4) and in F256 = F2[x]/P, P= x8 + x4 + x3 + x + 1. 26.1 #2,3,5; 26.4 #1,2,3; 26.5 #1,3,5
3/231) Find DES subkeys if 64-bit key is [100...0];
2) Encrypt [000000100000100] using one round of DES with subkey [11...11]; 		3) Which inputs yield F from S-box #2?
4) Find DES' Initial Permutation
4/2
FRI		 Use ByteSub in the AES to encrypt the byte `21' And to decrypt the byte `39'
4/9
FRI		 Determine how many primitive roots there are mod 3301,
and use a search algorithm to find one		 7.8 #1,2,10;   13.7 #2,8   20.5 #5,6
4/13Find the key using Diffe-Hellman, with prim.root 2 mod p=59, once you know X=20 and Y=3. 10.2 #2,4,7,8;   12.5 #2,5
10.4 #1,2,3 (header=98 for #3)
4/20Build a square-root oracle for n=1031*2003
solve x2= 3 modulo n=1031*2003 		12.6 #4,10; 13.2 #4;  13.3 #3,5;
13.8 #4;  15.5 #1,3,5,6,7
4/2716.1 #1,2;  16.2 #1;  16.4 #1;  16.6 #2 24.1 #1,2;    24.2 #1,2;
5/6Final Exam (12-3 PM) in ARC 207 Term paper due

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Charles Weibel / weibel@math.rutgers.edu / April 21, 2004