5.1.24 Affine Cipher.sagews

chr(65)

'A'

for a in [0..25]:
    a,chr(a+65)

(0, 'A') (1, 'B') (2, 'C') (3, 'D') (4, 'E') (5, 'F') (6, 'G') (7, 'H') (8, 'I') (9, 'J') (10, 'K') (11, 'L') (12, 'M') (13, 'N') (14, 'O') (15, 'P') (16, 'Q') (17, 'R') (18, 'S') (19, 'T') (20, 'U') (21, 'V') (22, 'W') (23, 'X') (24, 'Y') (25, 'Z')

f(x)=3*x+10

ord('M')-65
f(12)
mod(f(12),26)
chr(20+65)

12 46 20 'U'

Word=['M','A','T','H']
Scrambled=[]
for i in Word:
    x=ord(i)-65
    y=mod(f(x),26)
    n=int(y)
    Scrambled.append(chr(n+65))
Scrambled

['U', 'K', 'P', 'F']

g(x)=9*x + 14

Word=[]
for i in Scrambled:
    x=ord(i)-65
    y=mod(g(x),26)
    n=int(y)
    Word.append(chr(n+65))
Word

['M', 'A', 'T', 'H']

Word=['M','A','T','H']
Scrambled=[]
print "Letter  Number  Output  Letter"
for i in Word:
    x=ord(i)-65
    y=mod(f(x),26)
    n=int(y)
    Scrambled.append(chr(n+65))
    print i, "\t", x, "\t", y , "\t",chr(n+65)
Scrambled

Letter Number Output Letter M 12 20 U A 0 10 K T 19 15 P H 7 5 F ['U', 'K', 'P', 'F']

xgcd(19,17*18)

(1, 145, -9)