[HDCTF 2023]

爬过小山去看云

小山 Hill Cipher 希尔密码 发明者为Lester S. Hill

# 希尔密码
# http://www.practicalcryptography.com/ciphers/hill-cipher/ 

c = 'eightfourtwozeroeightfourtwoonezeroeighteightfourzerotwofourzeroeightfourzeroonezeroonetwofour'
if 'eight' in c:
    c = c.replace('eight','8')
if 'four' in c:
    c = c.replace('four','4')
if 'zero' in c:
    c = c.replace('zero','0')
if 'one' in c:
    c = c.replace('one','1')
if 'two' in c:
    c = c.replace('two', '2')
print(c)

y = c.split('0')
s = ''
for i in range(len(y)):
    ch = ''
    count = 0
    for j in range(len(y[i])):
        ch = y[i][j]
        count += int(ch)
    s += chr(count+64)
print(s)

[HDCTF 2023]Normal_Rsa

from gmpy2 import *
from Crypto.Util.number import *

n = 4785613888465991171479248142015453309149548888755453367991501772592797686075465426815591528773123474962122102667475893532087343900904799831474817826058951265607078893487357878501280782935653048309499430170214015422492927323961394806106719569168457890040223027119115392961801582406287167644266319898276785787730947633037300317098453409851410936140488150390919951503767522517809035474567
q = 6704006258427795304220450411280948926213189680360135534636452074716135019217911134480777251273836898349926894302122011679095979445240343891749741039976761
P = 6773247693445539441213578786581644136043035242620265251725630106817272212428325283262417364786451280269516220237289567904055371962564710888510272312707201
Q = 44943699913039047357456835559925378512493523252980366265686899925123157887149890185055864945749408514100461655676474535153113631214288057465776668291975220848776401405531599573114898492452990847774628035552581539370236080368457643523158920565504112005843410442573511095306233906498204203659537135943420051121
c = 2247027561636791381460194811205520085150851211795956750955965051548230844233212462525163107917067768507367576366327035846089534916090521357212722275045521111077106695721780943857231570836500588468487620819893688830570842176795906808347617421353983094639290979158413935035603633331786978227439155042365130799647385116773171906670409535157184391352888875130028955334874727206292146950544
e = 65537

p_r = n//q
p = iroot(P,2)[0]
r = p_r // p

gcd_ = gcd(q-1,e)
print(gcd_) # 65537

phi = (p-1)*(r-1)
d = inverse(e,phi)
n = p*r
m = pow(c,d,n)
flag = long_to_bytes(m)
print(flag)

[HDCTF 2023]Normal_Rsa(revenge)

from gmpy2 import *
from Crypto.Util.number import *

e = 65537
P = 8760210374362848654680470219309962250697808334943036049450523139299289451311563307524647192830909610600414977679146980314602124963105772780782771611415961
Q = 112922164039059900199889201785103245191294292153751065719557417134111270255457254419542226991791126571932603494783040069250074265447784962930254787907978286600866688977261723388531394128477338117384319760669476853506179783674957791710109694089037373611516089267817074863685247440204926676748540110584172821401
n = 12260605124589736699896772236316146708681543140877060257859757789407603137409427771651536724218984023652680193208019939451539427781667333168267801603484921516526297136507792965087544395912271944257535087877112172195116066600141520444466165090654943192437314974202605817650874838887065260835145310202223862370942385079960284761150198033810408432423049423155161537072427702512211122538749
c = 7072137651389218220368861685871400051412849006784353415843217734634414633151439071501997728907026771187082554241548140511778339825678295970901188560688120351732774013575439738988314665372544333857252548895896968938603508567509519521067106462947341820462381584577074292318137318996958312889307024181925808817792124688476198837079551204388055776209441429996815747449815546163371300963785

p = iroot(P,2)[0]
q = iroot(Q,2)[0]
r = n//p//q
phi = (p-1)*(q-1)*(r-1)
gcd = gcd(phi,e)
d = inverse(e,phi)
m = pow(c,d,n)
print(long_to_bytes(m))

[HDCTF 2023]Math_Rsa

。。。

from gmpy2 import *
from Crypto.Util.number import *

n = 14859096721972571275113983218934367817755893152876205380485481243331724183921836088288081702352994668073737901001999266644597320501510110156000004121260529706467596723314403262665291609405901413014268847623323618322794733633701355018297180967414569196496398340411723555826597629318524966741762029358820546567319749619243298957600716201084388836601266780686983787343862081546627427588380349419143512429889606408316907950943872684371787773262968532322073585449855893701828146080616188277162144464353498105939650706920663343245426376506714689749161228876988380824497513873436735960950355105802057279581583149036118078489
r = 145491538843334216714386412684012043545621410855800637571278502175614814648745218194962227539529331856802087217944496965842507972546292280972112841086902373612910345469921148426463042254195665018427080500677258981687116985855921771781242636077989465778056018747012467840003841693555272437071000936268768887299
a = 55964525692779548127584763434439890529728374088765597880759713360575037841170692647451851107865577004136603179246290669488558901413896713187831298964947047118465139235438896930729550228171700578741565927677764309135314910544565108363708736408337172674125506890098872891915897539306377840936658277631020650625
c = 12162333845365222333317364738458290101496436746496440837075952494841057738832092422679700884737328562151621948812616422038905426346860411550178061478808128855882459082137077477841624706988356642870940724988156263550796637806555269282505420720558849717265491643392140727605508756229066139493821648882251876933345101043468528015921111395602873356915520599085461538265894970248065772191748271175288506787110428723281590819815819036931155215189564342305674107662339977581410206210870725691314524812137801739246685784657364132180368529788767503223017329025740936590291109954677092128550252945936759891497673970553062223608
e = 65537
# pbits = 1024
# PR.<x> = PolynomialRing(Zmod(r))
# f =( x^2) - a
# ans = f.roots()
# print(ans)

p = 135098300162574110032318082604507116145598393187097375349178563291884099917465443655846455456198422625358836544141120445250413758672683505731015242196083913722084539762488109001442453793004455466844129788221721833309756439196036660458760461237225684006072689852654273913614912604470081753828559417535710077291
q = n//p
phi = (p-1)*(q-1)
d = inverse(e,phi)
m = pow(c,d,n)
print(long_to_bytes(m))