2023ISCTF
2023ISCTF——Crypto题解
Crypto
easy_rsa
rsa_d
上面两题p,q
都给了,白给啦
七七的欧拉
$n = p^8$,计算$\phi(n) = p^7\times(p-1)$
exp:
1 | from Crypto.Util.number import * |
夹里夹气
1 | 嘤嘤?嘤嘤? 嘤嘤?嘤嘤?嘤嘤? 嘤嘤嘤嘤嘤?嘤嘤嘤嘤嘤? 嘤嘤嘤 嘤嘤?嘤嘤?嘤嘤嘤嘤嘤? 嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤?嘤嘤嘤嘤嘤嘤 嘤嘤?嘤嘤?嘤嘤?嘤嘤? 嘤嘤?嘤嘤?嘤嘤? 嘤嘤嘤嘤嘤?嘤嘤?嘤嘤? 嘤嘤嘤嘤嘤?嘤嘤? 嘤嘤?嘤嘤?嘤嘤?嘤嘤? 嘤嘤?嘤嘤?嘤嘤嘤嘤嘤嘤嘤嘤?嘤嘤嘤 嘤嘤?嘤嘤?嘤嘤? 嘤嘤?嘤嘤?嘤嘤嘤嘤嘤? 嘤嘤?嘤嘤嘤嘤嘤嘤嘤嘤嘤 嘤嘤?嘤嘤?嘤嘤嘤嘤嘤嘤嘤嘤?嘤嘤嘤 嘤嘤?嘤嘤嘤嘤嘤嘤嘤嘤嘤 嘤嘤嘤嘤嘤?嘤嘤? 嘤嘤嘤嘤嘤? 嘤嘤?嘤嘤?嘤嘤嘤嘤嘤? 嘤嘤?嘤嘤嘤嘤嘤嘤嘤嘤嘤 嘤嘤?嘤嘤?嘤嘤嘤嘤嘤嘤嘤嘤?嘤嘤嘤 嘤嘤嘤嘤嘤?嘤嘤? 嘤嘤?嘤嘤嘤嘤嘤嘤嘤嘤嘤 嘤嘤嘤嘤嘤? 嘤嘤?嘤嘤?嘤嘤嘤嘤嘤? 嘤嘤?嘤嘤嘤嘤嘤嘤嘤嘤嘤 嘤嘤嘤嘤嘤?嘤嘤? 嘤嘤嘤嘤嘤嘤 嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤嘤?嘤嘤嘤 |
嘤嘤?
换.
,嘤嘤嘤
换-
1zRSA
1 | from secret import flag |
根据勒让德理论,题目中已经保证了$|\frac{N_1}{N_2} - \frac{q_1}{q_2}| < \frac{1}{2q_2^2}$即$\frac{(p_1-p_2)q_1q_2}{p_2} < \frac{1}{2}$,所以$\frac{q_1}{q_2}$是$\frac{N_1}{N_2}$的收敛子
连分数展开即可求得$q_1$,$q_2$
exp:
1 | # sage |
signin
1 | from Crypto.Util.number import * |
考察Schmidt-Samoa密码系统
$\because Nd \equiv 1\mod (p-1)(q-1)$
任意选取一个$a$,有$a^{Nd}\equiv a^{k(p-1)(q-1) + 1} \equiv a \mod pq$
$\therefore k\times (p\times q) = a^{Nd} - a$
和$N$求公因数即可得到$p\times q$,再用d解密即可
exp:
1 | import gmpy2 |
EasyAES
1 | from secret import flag,key |
padding函数是在明文前面填充\t\t\t\t\t\t\t\t\t
再根据flag
开头是ISCTF{
再利用CBC加密的特性,爆破最后key
的最后一位以及iv
即可求解
exp:
1 | from Crypto.Util.number import * |
ezRSA
1 | from secret import flag,key |
Part1
设getPrime(256) = a
$$
\because leak = (e^2 + (ed-1)\times k!)a + k
$$
$$
即leak = ae^2 + (ed-1)\times k!\times a + k
$$
$$
\therefore leak -k = ae^2 + (ed-1)\times k!\times a
$$
因为$k!$非常大
如果用leak - k
模掉k!
,得到的结果就只剩下了$ae^2$
如果用leak - k
模掉(k + 1)!
,得到的结果肯定是大于$ae^2$
判断最后的结果是否和$ae^2$为一个数量级,就能求出$k$
求出$k$之后,我们就能求得$a\times(ed-1) = t\times \phi(n)$
用$t\phi(n)$代替$\phi(n)$就可以求得$d$了
part2
$leak \equiv p^q\mod n + q^p \mod n$
把模缩小
$leak \equiv p^q \mod q + q^p \mod p$
由费马小定理得
$leak \equiv p +q$,联立$n = p\times q$,解方程求得$p,q$
其实$p$可以在lcg中求
下面是求解LCG得到$seed$
最关键在于$key$
$key$实际上是一个为素数,根据题目给的
1 | def is_prime(p): |
如果以这个代码来爆破$key$的话,速度太慢了
只要把函数修改为
1 | def is_prime(p): |
原因是,满足$2^{p-1} \equiv 1 \mod p$,$3^{p-1}\equiv 1\mod p$,……,$97^{p-1}\equiv 1\mod p$的数,一定满足,$2^{p-1}\equiv 1 \mod p$
修改后的函数相当于求的是原来集合的母集
然后遍历母集中的元素即可找到$key$
另外可以查卡迈尔数的表oeis.org/A002997/b002997.txt
exp:
1 | from tqdm import * |
baby group
学艺不精,理解了好几个晚上才理解 >ᯅ<
task.py
1 | from Per import P,Block |
Per.py
1 | import random |
output
1 | [82, 237, 32, 83, 30, 200, 116, 114, 4, 147, 171, 152, 193, 19, 170, 136, 186, 8, 124, 159, 225, 6, 180, 125, 74, 14, 255, 60, 187, 132, 222, 121, 56, 79, 57, 229, 87, 27, 72, 197, 201, 191, 75, 38, 135, 177, 165, 149, 17, 172, 173, 59, 210, 108, 31, 142, 163, 227, 178, 226, 73, 256, 190, 12, 103, 238, 129, 157, 219, 131, 67, 28, 68, 236, 168, 209, 245, 93, 61, 122, 208, 137, 49, 94, 111, 18, 161, 106, 54, 175, 70, 16, 110, 5, 218, 81, 233, 45, 91, 188, 151, 104, 148, 184, 228, 248, 150, 176, 167, 35, 130, 242, 126, 156, 42, 169, 232, 102, 50, 214, 179, 205, 9, 235, 97, 84, 246, 36, 76, 240, 52, 144, 98, 86, 99, 21, 64, 217, 15, 202, 206, 55, 244, 65, 23, 53, 250, 78, 22, 215, 25, 66, 143, 107, 195, 80, 196, 254, 174, 33, 162, 252, 141, 153, 43, 185, 211, 220, 115, 127, 216, 251, 139, 95, 146, 48, 239, 241, 37, 199, 13, 160, 90, 223, 123, 181, 120, 164, 118, 112, 128, 192, 249, 39, 2, 207, 71, 182, 145, 62, 3, 92, 183, 194, 100, 24, 133, 10, 117, 234, 29, 11, 140, 166, 85, 224, 230, 134, 189, 63, 46, 58, 231, 247, 47, 154, 44, 77, 89, 101, 69, 40, 26, 243, 253, 41, 51, 105, 155, 138, 1, 212, 20, 203, 213, 198, 158, 88, 109, 34, 119, 221, 113, 96, 204, 7] |
求解本题关键在于求解mask
和msg
先讲讲对msg
的求解
求解msg
$\because c \equiv r\times h + msg \mod q$
而$h \equiv f^{-1}\times g \mod q$
$\therefore c \equiv f^{-1}\times g\times r + msg \mod q$
左右两边同乘$f$得
$fc \equiv gr + f\times msg \mod q$
两边再同乘$f^{-1}$得
$c \equiv f^{-1}gr + msg \mod q$
在此基础上,两边再模$g$得到
$c \equiv msg \mod g$,因为$g < q$
所以求解$msg$之前,我们需要先求解$g$和$f$
对$h \equiv f^{-1}\times g\mod q$两边同乘$f$得
$h\times f \equiv g \mod q$
即$g = hf -kq$
构造格
LLL规约后即可得到$f,g$,然后求解$msg$
求解原始P
思路类似于2023BRICS + CTF——sqrt,题目给出256个元素的全排列$P$的平方$P^2$,要求我们通过$P^2$恢复$P$
参考:Crypto趣题-其他 | 糖醋小鸡块的blog (tangcuxiaojikuai.xyz)
首先理解一组排列即是一个置换,而排列的平方就是二重置换,相当于C[i] = P[P[i]]
举个例子
上图为一个置换,表示q0
置换到q1
,q1
置换到q2
,…,q5
置换到q0
这个置换的平方就是,q0
->q1
->q2
,即该置换平方后q0
置换到q2
平方后,该置换变为:
那么还原的方式就是将两个环并排,然后挨个插入,如下:
插入后为
如果以这种方式插入的话
插入后的结果为
很明显,不同的插入方式,恢复的置换是不一样的,但这两个置换的平方是一样的(这个结论有助于理解后面恢复原始的P)
上述是偶数个元素的置换
下面我们讨论奇数个元素的置换
该置换平方后是
可以发现,奇数个元素的置换平方后,环并没有断裂,只是位置上发生了变化
这种情况下恢复的置换是唯一的
理解上面内容后,即可开始做题
1. 首先要先把平方后的排列切割成若干个环
就如
我们发现q0,q2,q4
,q1,q3,q5
能构成环
所以我们要在P^2
中找出所有环
1 | def find_Chain(P2): |
发现找到了2个长度为64的环,2个长度为29的环,2个长度为20的环,2个长度为9的环,2个长度为4的环,1个长度为3的环,1个长度为1的环
2.分析如何还原
对于长为64,20,4的环,它一定是由长128,40,8的环拆分而成
对于2个长为29,9的环,有可能是由58,18的环拆分而成,也有可能是两个独立的长为29,9的环(这种可能的概率很小)
对于长为3和1的环,就是单独的环
本题我把2个长为29,9的环认为是由长为58,18的环拆分而成的
需要注意的是把2个长为64的环拼接成128的环有64种可能,其他也是一样的
首先恢复单环,然后拼接双环,最后恢复出初始置换
也许讲的不是很清楚,建议结合参考文章看,或者与我私下交流讨论
exp:
1 | #sage |
Misc
Beyond Hex, Meet Heptadecimal
题目描述:
我:给我来个自创的古典密码编码类型的题目
chatGPT:明白了,你想要一个编码题目,但它应该有一些非传统的编码方式。让我给你设计一个类似的题目。
你获得了一段看起来像是十六进制的字符串,但解码后得到的内容并不是预期的文本。你需要深入挖掘,并发现隐藏在其背后的秘密!
密文:
ID71QI6UV7NRV5ULVJDJ1PTVJDVINVBQUNT
根据题目意思,不止是16进制,猜测A
对应10
,B
对应11
,以此类推
然后把密文中的字符转成对应的数字
然后发现这些数字最大是31 = 2**5 - 1
,猜测有可能是要把数字转成长度为5的二进制串,然后拼接
最后长度为7进行分割,因为这样刚好能表示0~127
的值,就是ASCII码的范围,再转回字符
exp:
1 | #先生成字典 |
你说爱我?尊嘟假嘟
密文:
1 | 你说爱我 你说爱我 你说爱我 你说爱我 你说爱我 你说爱我 你说爱我 你说爱我 你说爱我 你说爱我 你说爱我 你说爱我 你说爱我 你说爱我 你说爱我 |
三种不同信息,尝试Ook
你说爱我
->Ook.
,尊嘟
->Ook!
,假嘟
->Ook?
Ook解密得到ild3l4pXejwPcCwJsPAOq7sJczdRdTsJcCEUsP1Z
base64解密:ISCTF{9832h-s92hw-23u7w-2j8s0}
张万森,下雪了
用题目给的字典爆破压缩密码为blueSHARK666
得到tip.txt
,发现是非常长的数据
尝试多次base64解码, 解了17次后发现无法进行
最后得到的信息为
1 | CIcTpGI3CjMSCTYFdoCTNIIXpIbXZ0ISCadICZI39IbSJYII2CMISxSnSjIE5YFmxaeISXNICSZTp0SmpIYSCXFXdIMGZTSmxacSCICIdTbIpSSmpCYSTXCXTFaFxqFm2IcISCNFNSSmZySmxaC2CIbDZIZCSTSDIadGIGFTdSZF0ESCIaYIZ0S30jZ2ZOY3CIIICGITdSMSS5FF5OSGJGImIIa2C2S3CZeIdICGpSZnB5I3S3b2FyI3djZIpXYICZeITFZmIjMF52SG2IF2YCaG9IbX00CDAIeGJSIT00M2JxIS0IS2dIbICXbXZSYTSIMITSa0NXZTpCSF53SmJFZT0IMIpXYFxac2dCbINNSXACSmxjeE20FX0FbGZYSTdoISTIaINIMSJXSm5OC2JIcETFbIF2YFCacmJESmIISnBFSmxaYF5IInSXbGZpFm5CeSCqQmCIMF5GC2CoaSJFSm9FSm0DFFxadGNIcE5IbIY2SIxob2C0InNCbGZaYT0IM2CCeGIjSTJTC2CIFFJZITpXbIC0CDJ3Z2dYaIZ0Mn0XIIxobFZIITSZIG0FSmCaeTTSImC0ZTS5CEZIS2YCQ30IMjIXSjIIdSZCbINSZnBaSTdIIFSyIX0XbTJOS3C3cTZSF3NOZTpTCTCOaSJZbDCISCSTSm23Z2NFcIdNZnByICJ4YSCIInZ0Z35XFTSINTCIF3CNZ2I4S203CTCCaIdCS2MxSTCIcTCFCIZNIEJXSjSxMIdGIXdXaF0aSTdIeTTII3CXS3CCY3C3aSCISjNIbXB0SG2IZFNIImIIMn0FIIx3bFSIIT0jZF5aSm24IIYyNSNFMSpICTCISmJYa0pFbIpyCI2OZ2p0aINNIEJYS2ZCYIExC0JNSIZYYmxIIITIaE9OZmC4SFCTa2CCFnpCMIpZYSCOZTNIITdSZT4TSGCaFmSIFTTSZTCoCIx3b2CXcECOZTp0SIx3SFJZNSBCa2p2CFCIZTdZOSdISECXSGxIQ2YyITT0IEpXYCJICI3yMF9CZTC0SF2IS2JIb2TIMSJDISdNeIdICIZSbIpoSITxFFNGSnIIa2ZYSm2IIICCMDS0ZCIXY3ZOSSCCaExIZ200FjIOcFIGSTdNMEpCSm2TYIMxITdCb3pQSmx3SITZInCTZTpyI3ZIaE2ZIT0IMnZ0SjI3IISIbIp0MXACISSac2CICnJPS2BOSjIJeICIY20NZTS5FFx3SGJIcITCaFZICDI3S2CFZTdNIEJSSm24IFIIIX0CbmxXFmxIaIpEITdjMIZCY3dIFT2GcITIZmQICDJISFECCI0SSGxCIICacT5IIT0NSCTYFmxIeT3IF39IMDISSIxoSmJYaDNSMGZPFTd3Z2pGCGT0M0BMSmTIeGQxCnZIa2pPSTdoSITFZndFMSpTCSZIS32Xe0TIbCSZSTC3c2NIaI00M3TxS3dCeIYxC0S0ZTpOYmx3b2dXdGICST24I30IaTJCaG9FSm0DYjI3S2dCdIZNSXAIS3dTa2YyI300Zm0SS3SaCIYIImIIMIZTFmxISFEydCIISEoIYCICeSNZCI0SSGxISmxaI2dGITCXbFCCCSdIMISCMCBFbFp0YTCISFIZInCCe3CCYCI3cFIGImTIZ20YS2dTYSMxC3dXIGZYYTSacTSqQCIIMSI4SF2TST2ZcEpSS2B0SjJGcmECaICTa2p0ITCaIFZICnZjZ35YFjJob2CZImpNSTJTSmC3IId0FT0Ia2p0STCIS2pGCmxIbEp6SjJCNIIGInJjI0BaS3F2cTCqI3CIS3pxSGxaS2JIcDCIa3J0SCI3IINZCIdSZF0FSIcxb2TIIX0CMF0IYXpGISC0eGCIM3pyCTC3ImEyFTZCMSpXCEdIIIJCeINSIEJ3S3CIF2YxITCNSmZqFT0CYSTFZ3CXZmZXSFCTIIJIIn0IZ20ZSCI3SFN0OS0XIEJMSXpGI2YxSnSFbGZpFjI3d2CCcECSMSJCS20oIGJYFTBSbXN4C3C3cTCCOSCNa2Y2ISSaF2dCZX0jZF0XCFCIaIpISCIIbIJCSmx3aSNIICJIbCB2CFCJeIpSCT0XZ2JQSmTxb2Yxb0N0ZCTIY3d4S2YydDB0bFYFSmx3SF2IcDNIMIpPFmxOcFJGCIdISC02S2CIZ2dCS3daIICIY3F2cIYII3CSZmZXSII5F32SNXpIMn0SY3C3NmJSQTSIM2JoITd4YSN0F30PSFxCYCNBd2dISmISMIZCSFCaIGJXaG0Ia35SS3CZeIS0dGCIa2B6SFCaaFIIM0dCSECXYCI3IIdIITCTZTpCY3CIaE2YQn0IS2Z0ISC3ZFJGaGCCZ2JQIICaIFSIIXTTIGZoCFZGZTSCe0dIMSoFFm5aSFExcIBSbX0PYCJOZ2p0bI0ISXBISm24F2MxIX0CIGxSYCIIIITZSCIjZTCCSIx3S2CIcE0IMjEISmIxZSJIaIdSSICFIICaIFNZNS0PSTpoYCBIISCGF3djbSI4I30ISIJ0F39IbG0DCmx3SSICdGTNS20YSCJTYIIIInZ0Zm0aSjNIaIYIInNObEp2I3COCmExcEpXS2Z0YjISeSJYcIJSSSpYIIxoFFIGCIdaZSpIFmxIITTSITd0S3T4FF53S2C6ZCBaZECZSjJ3ISNCZTN0eTCaSmTIeE50SnNXbTJIFjNISTZIIndTbGC2SF5OITCIcI0CMIpDSjAxIISZaISSIG0MIXp3Z2SyC3COS35pYCBINSCCcEdCSmxXSI0oIId0aITCbXZ0SjIIcTpGCmpIbIoISGxIC2dGInZSb0BaCFCCd2CFQX0IbFpISIx3SFSIITSXSTp0FCJIIIJZCICSZTpYITdTYF2ICI0jZIZaSjI3ISC0dGI0MFpSSmxIImEyFXpFSTp0STC3dE9XbE50MXBCSTZJMSFyZ3dCb35FY3doSTCICINIZTpySF2GF2CZcDBSbCEISCIaZTdIcIdIZSpyI3ZGFFMxC0SFbIxOCIx3ITdXdGICS2JCY3CIFFJSQnJFSSJ0STC3cTdICm0IaFIFISSaa2dGIXpSb3pXFjNONICqZmC3STJCYFdoC32ScDSIbGZ2FjIIS2ZFCmTCZXBCIIxoF2CIb0NIbmZIY3CaMI3ISCSXZ3pCYTZCS2YCQm0XSTp0STCIc2IIcE5SaCETSm2IZFEyF30IaFZSYTd4b2ZSaENSbIpTCFdIaT2EZT0SbCSCSjJ3c35IbIpSIG0MICIaSFMxcEdFbG0XYT0oNTCqIX0IMSp0FF5OaTJXeICCa2paCDIISTdCZmpSSCSGSSd4a2YySnNXa2CXYTZCNIS6ZmCIMSp2FmxIaSJFQTBIbCAxFCJJeIpGSTNSSSpISIC3F2dISnZ3Z2ZaSmCISTCCeG9ISTpCSFpOS32FaG0Ce3CXYF2OZ35ICG0Ta2S4SmxjeE50ZX0XaF0FYmI2SSTIFnNIMSJISF2GSSJIc00SbCSPSTCJeINZbICSIG0YSTZ3I2N0FjCZbGZoYCJ2MICGSmCIM35yCSC3aSJZcG9FSm0DSTCadGNIOITNSnBSIICaYSTIInZSb3CaYCJISIpIInNjbGZTCEdoFT2GICIXa2CCSCICeSJYaIZ0Mm0CSmTxF2CGSnIIaCTqCICIISTZI390S35GFFpOSFJFZXdCSEExFjI3IIIGaGTSZXBQSm2TYSMyCnNSbG0IFjBac2TZIndXSTJCSmpCIIJZbDNCMIp2SjIaNTCZaIdNa3CMSIpGaFZ0Z3dXaCSCYmC3NSYxF3COZTS5SIC3SGJZNS0CbGQTSTCadGSSImxIb0B6SjSxMIZIIXdNSIJXCSdoeTCFI3CjbF5SC2CIS2JYQjJIbXB0ISdOc2dFFTNSIEJYII2TI2dIInICa3JOFm2IIIYxaGC0bEpYYFCoSSC6SnCCMn00STC3dIJIaId0MI94Smp3NGEyZTdXa2pFS3S3IISqCTNjbIpYCSC3ST2IIjIIbX0XYSCJeIIGcIdIMTJSSXp3ImSGC0N0ZCSYFTS3FICCMCZ3MIZ0SF5IC2CXFTdFS2ZXCmxaIGSGCTdIb0B6ICBIb2CXZX0jZTC0Sm2IFIZCeGIjMXB0I3F2SIJScECIa3CCFCISeINYaI0SaCSCSjBoQ2YxbI0je3CYFm24ISpIaGCIS3pCYT0IST2FFXdIa3C0YFx3dINGcE5IMFoyS2CISmQyFX0Fb35CY3dIC2TCMI9SMST4SF2GSIJII30CMICZYFC3c35XOSSIMF0MSjBaa2d0F303ZFxOSm5CISCCMDIFMST5FF5ISmJ0eI0CbG0SCIxIcTdCdGpSZTp5S3cxb2FxI3CXbGxXYTZGM2CFZTp3MDICFmx3aSJScITIZTCZSCIIZFECbGpTa2pYSIdTd2NGa2dXbXZICSCIIIYyeGIIM3pSFTZCIICIcGIaSTpXYFx3c39ICGTCZFpYSjI3MGEyIX0XaFZpFTSIaISZSCIFMSpTCSCObGJGcDBaSIZ0STFxSFJECTdNbTJ6SmTxI2dIZnZ0ZmZXFT0CCSCFQmCIMF50FF5OSFJ0FT0CbXZTSGxac2pEQTpIMIYTSjIob2TIC3CjIEpIYTZGSICEZnNXST50I3CICTCFQTdISEp2SCJGZ32ICId0aCSISmx3bFSIbICXa2ZXSmCIeTTSImC0STpyFFCoS2JIIm0Ce3C0SjIIdSNIQTdSS3pQSmTIMSICS3dXb3paCCJoSIZIITdOSTS5CFdTS2SIcDISS20CSjJ3IIIIeICNZnB0ITCSeIYxcE0jZCSXCSSIaIYxITd0MFT4SFC3SId0aISCa2p0STCIdGSSCGpSZnBISSCob2FIMS0Sa3CXSnpId2CFQXdTZ35TYFC3aSCIICJIZTp0FF2IIIJYcGIIbI0IIS0IS2dICI0TZmZZCSF2IITZImIIM3pGCTCoSSYCFT0Fa2pyCDIIZTpGcId0MTJSSmp3d2QxInJNSIZXS3SaIITXd0dCZTCxFm53SISIcE0XaFZSSGIxZmN0OSdSSESTI3ZGCmQIMSCaZmZYFjJoSSCqQmCSM3C0ST03S2CIITTIbCETCFCZemNICI0Ib0AIITSaYSCZMXIZSECXCI5oaIpICIdIMIZCSF2IIIJZIXpIMSpXISCNeSZYbIS0MTJCIICad2Qxb0ZTZIZOCSCIeISXMFdXbIT2CSZIIGEyaE0ISEpTFjJOISIICE5IMFoySmpGYSTXF30Fa2pZFmx3C2CqZ3CCbIpYCSZCITCIbDSSMnZSSm23IGIGCIp0MXBoSIZGcFNIInZ3ZmZOSmxINSdZSmIIMSJTFmpaF2CIIT0FSCSCCGxaZSJIcGxIaCS5SjJCNSdGITCjZm0YSjNodTTqQXdTZT5GSmxOaSCIcIpIS2B0ISCOS2SYaI00M2JIIICacT5IbICXb35XCICaeSTFcENXbIpGSF5ISFIZITBCMn0ZYCIIdGI0eGTXZF0aSmpGaT50IXTCIGxXYmI2S2TCcCIXSmxySF53a32Ic00SbCI0S3d3ZFNIbISIbFTxSm2CeGNICISCbGZpSTC3NTCqQmICS3pCSG5ISGJSQm9CSEC2YjI3cTCCZTZNS2JCSI2TaFIGIXTTZm0SSnpGdTYxITpTS2CSCEF2FFJYaI0IZTCSYjI3IINFCTZSaCSXISdCMSCGa20XbE5XCICaZ2C0eINSM3pCYFCoSFIZbDZFSSp0STCOcTdCcINISnBYSm2IC2FIM00Xb3CFYCNIISCqQmICbIS5CFC3aIJFZnpSMnQTSTd3Z2dCaI0Ib0BySmp3C2JIC0JPSmZpSjJoSTYxITNFMFS2CS0OIGJZNSdCSEExISCacSJZCE9IbSJ5SmTxMGIGInJOSIZaCFCIeTYyeGIIaCSXSIx3aE2YQTTXa2CZSjIOSFNII39IaCSISjB3CT5IInZ3Z2BZCFZIIIdZSmCIZTpyYT0GS320FCBIbX0CYFx3dSpINF5IbXcxSFxIa2SxIXdNIEpPST0CS2ZXNI9NMSpxFFCTST2SNXTCSSpSYSC3cFNSbId0MFpSSCSxS2NGFnJXbFCCCI2oSSdXeGICMTI4SFxobIJ6bINFSTC2STCCeF5SdI0IM0BXSjSINSCIInNjZI0SYCIIYSpSCEdCZCTXI3F2aETIICIIaFQTYCJJeIdFFTNSa2BSIIx3b2dGbISIbmZYFm5CZ2dZI39IZTp2FICoITCIc0JCSTp0YF2OIIJICE5SbEpCS2CIZ2NCS3djZIxSY3docISCe0dISmZXSICTaF2XF30IMjSXYIx3dISICICSSECFSjBaImSXF3SZbIpOYCNCIIC0eG93MIZTFT0oaTSyaGIIbX02YFxIcSJZOS0IMDSSISS3c2FIMSCIa35XCSC3I2pSITd3ZTpCI3CIaIECQndIS2BDISCaZFJSCmIIemxyIIC3FFSIC0JSaT5YY3CIeSZIIm9IMDIxSmCoSFExcG0SbX0ZCEC3c2p0bI0IMmcySmC3NITIIXTSa2pPSmxIcTSCe0dFMIxSFm53CFJGcICSMI0SSCAxSFNGaIdNaTCQISd4I2JZNSd0ZTppFm5BeTdIImI3MST4SFxIaIJCFnBSMICTF2CacTpScE5IMIpJSmT2C2d0ZXpZbG0aSjNIMTpEZmCIMIZCFF24FFJIImIXSTC0YjJGIINZImpCZ20YSmpOF2YxFTdXbXZCCICIITC0eGI0ZCIISmxCS2JIc0CSSECaCFCIISNIaGTXZ3pFS2d4S2dZMXNIbTJIFnpIISSqQTdOZmC2YFdGIGJGcDBIS2QTSm23SSJIQTC0a2poIXp3Z2SxcE0SZ35YFTSIFICCM00OZTS4SI0oSId0aISIMGZSS2CIdGS0ZTdSZ205SjS2aFIIInNXbm0IYT0Zd2YICECIM350Y3CISFJIcISIbXZICFC3Z2CFCm0IbSJYSIZ3bFSIInICIG0XCII2eTdZaE9XZTpJFI5CSmJYaDJaS200STCGdIJCcE50eTYFSmTIMSQxIT0CaF0IYXpIS2TFZmICSnBISF2TST2IcDBSbX0TSGxadGZ6QTd0aF92S2CaSmSIInSFbIJpFjJoaICCcE9SM3C0SFCaIGJZc0NSbCICCIx3cTpSCISSZ2J0SCJTc2YyZXTSaTpSSmxISIT6ZmCjM3p0FFx3F2CFQTpIMIQTSCIIdT5SCGpISTpFIS0ISFMxSnZTZXZYY3d4eSYyeGC0ZTT2SmpaSTYCaE0Ia3pTSTCGcSSIcG00MXBCSm2IZFEyFTdIbTJIFmx3SIZISndOZTpCICNoC2SIMCNFSI0SISCOZmN0ZmIIMF0oIIpGYIMxSnJaZm0CYT0ZeTdISmpOSTT5FFC3aISZcIdCbG0CCGxacSNZdI0IbEp4STd4aFI0ZXpZbECXSjNCCISqZ3pTZnBJFFI5ST2Ca0dISCAxFCIZeIdFZTNSSSpSSISIS2NGI30OS35XCICIeTFyeINXbIpGYnpCS2CIInpCMn0ZCICIIGNGCmTCZF3xSm2IImSGIX0IIG0FYmx3S2TCMCZXZTpxSGxOamJGbDSaSIZ0YI23SmNIITdIMF0FISSSeGZ0Z3dIbGZpSTdoeSCYcEdCbSCXSI53IGJIIT0CbIpTCDIadGZGCIdNZIC6SFCoC2TII3dCbFCXYT0IeTZZImCjbFC0SGxaCmECQTpXbICICTCCeSNISTd0MDSoSICIYIIGIXdaZmZFFTZIIS3ISCI0ZCB2FFCISFJGI3CFSTpICSC3cTpGFmTSZXBYS2d4S2TICEdSZm0qCICaSTZIaENIMST5CSS3aGJScETIS2B0SjIJemISITpIb0BTITSaC2dIcEdaZmZIYCIIM2YxITNCMFT4S20oSIJ0eG9SbX0TS2CIcSJZdI0Ib0AISGxoa2SZMFSIaF0XSjNoaIYICECIM35JSGx3aSdIMCZXbIp0YCJOcFNIbGIIb0BPSmxoQmSGITdaZIJZCSCINSFyeIdSMSpGFFxISFJFZTZSMIpXY2COc39ICmTIb3SFSmxjeGSxFnZCa2pqFmxIIIZIInd3b0BIFmCIbIJFQ3pIZ20SYSCJeIIGQTdSSIYCIXpGImSGSnNaZm0pYTC3eTdXdGCNZCB4S20IC2CFbI0FSSJ0STCIdINIdIdNa2BaSSd4Q2YyITSIa20XCSCISI3xITdjMIZTYFdoC32IcE9IbX0ZCDIJeGJGaISXZF0XII24IFNGSnZNS35YFm24MIpISjBXbIpCYTZCYSJXF30IMn00YCJ3ZSCICIdSSF05SmC3NITXF3dIb35pFm5Cb2ZXeECNbIpySIC3ITYINXpIMjSTYCI3dISZOSdSIISCSjJ4aFNIInZIbXZOSmCSd2CFIjB0M3CCFFCaSGJXaI0Ca2p2YFCaSTdCZmpIa2paISS3dFIIITSIaFxYS3S3aIdIITp3MDIJY3doF2CIcITXSmQIYCA2Z2CFZTZ0emxxSICoQ2NIInZTZ35oSmCINIFyNIIXZTpCFFCoYSJIcI0Ia3C2F2COcFI0bIdIb3JXSmCaaFSCS3COSIZYYmx3FICCcCISMSCTCE0OC2CFQTdIMn0PSjAxZSJZaIdNbTI2S2CaYIMyC300ZTCCSjI3SSCFQmICMTJSFmCaC2CZNSZIbCSDFCIacSJCdE5IbX0CSCIob2dGCE0TZTCaYT0IM2CSImI3ZCIYC2CoFFJIcI0IMnZ0SDJIeSNZaGxCZF0XIIxobFIGbISZIG0XCII2IIYyeGI0STpGSFpaSFEyFCBXSmZOCSCOIIN0ZTNSSF0FS3CaYIQIMXNXb3pIYCJIS2TIImICZmZyYFC3SFJScIpCSSpCSF23ZFNIeIdNSnBoSIpGd2NIcEdFbIxXYCIZd2CCcEdSM3S4Y3C3SGJ0eIdCaFZSISCIcTdIImxIbIp4SIT2CFICI30Sa3CYYCIIcTC0eGI3Z2SFFmxoSFJGc00IZ200SF2IS2ZFCmTIMm0FSIcxb2dIInZNSIJZCSC3IITZFmISM3pTSIxISFJYaG0aS200FTFxISZICE5Ib3I4STC3NITIIXTCaF0IS3S3ISCCMSNSMXBXSF2Ga32YQ3TSbX0CSCI3ZTNCZTdNS2EISmpGc2YxCIT0ZTppFjJoeIdICDBCST24SF5IbIJXFTBSbX0CCTCISTSICG0Ia2B6ICBoc2dZMF00I0BXY3dICISqI39CST50I3dIS2JIcE5IbGZ2FjJIeSSIaIZ0Mm0FIIC3FFNGSXdIa2ZZY3CINSpIImC0ZCIXFmpIS32qSTZIbCIGCFdOZ2IICGTXZCETSmCIZ2YyF30IaFxSYXpIcISCNFNOSTpxF20oFT2IbDNFSm0TSjJGc2NIaISIbSJFI3d4a2YxC0J3Zm0CCFCIISYydGI3MIZ0SGCaSGIIcI0CS2ZTYFCINTNZOIpNaCS0SFCaSFIIIX0CbICYSjNodTCXc20IMIZ2FmxIaGJIc0CIZmQIISdIS2SICI0SaCSXIIxIST5IcICXbFCXSmxIeT3IF39CS3T6YFdoSFJGcIBCMjICFjIIc35XaGxSZnBJSmTxNGEINF0IIGxCYCIIC2YISndSZTS2YFSOIIJIIn0IZCA2YI23Z2dFaICNbm0QSTZBeIYxCnIIbIpOYICaMTCIF3J3MTC0SG5IaTJCaI0Ca2C2SSCaS2SZCG0NSIITICBIaFIGIXp0ZTJ0SnpIMIpEZmIIMXBIFIxISFI6S3TXS2ZSFCJGZ2NIbICSZ20XISdTI2dGFnZTZTCYFTZIS2pIImCFbFS6FI2GSFJ0CjZCa3CCSjI3dSZCcIZIIEJoS3CjMISyCnNjZSp0FmI2SIZIIndNZmxySF2TIIJZcIdIMI02SjJGcTdCaId0a2p6SmpGC2dXZ3d0Zm0CCCJoSTYxY20NZ2I4SFx3aSNINI0SbnBCSTCIS2dZdI0IbXQCSmTxMIdGInJjI0BXCIpIdTCCMFCXSTC0FIxIS2JIcG9XI0B0SDJOS2JFCmpIMm0PSjBII2SIIX0XbFCaSm2IMICCeG9SM3S5SI5GSmJFZTZCa3CCSjJGZTZICIdSIEJ0S2ZCST2GI30CbGZYYCJoISTFIm9SZmZXSFCTa2SII3pSS200YFdIeTIqITdSZTpoS2C3C2YxInSSbEJXYCNCFIdIa0dIaCI0SF5ICTJIITdFS2ZXC3CaIGZ0ZTSNSnB5SCJ4b2dCI300IIpXCFCISIT6ZmC3SnB0SG2ISIJScE0IbIpqCFdJeICYbINXIEJCISd4YSdIInIFbE5XFm2IIIYyMFd0aCIYSIxII32GcI0Ia3CTSjJOZFJGaIdNMFpSSFCII2SxIX0IbTCIYT0oSIYII3CTSTpTCF0oS32IInpXaF0TSjIaZTdCOSd0aToCSjIac2CCZ30IbGZOYCNCYSCICDBSMST5FFxIFFJ0aIdCS2Z0YFxINTJFCINNIEJJIIC3bFJ0I3dSe3JXYT0ocSpEITdIMSpCY3CIaE2IITpXSCETFCJOc2CYCI0SbSJISIC3NGSIIXTOSCTSCSSIMICXNXNIMST6SIxCITCIcG0IbIpTYCIIZ2CICGTIIEJISm2IQFExInZIaFZ0FTCaISTZCINSMSJYCFSTSIJCFnpIMjEISCAxSmJEFTpNZTpyISd4ImSXZ3CPSnBoCSCIISCGF3dCS2JGCSCIYSJZNF9CI0BGCSCacTdCOIpNSTY2SIxoc2CCI3djZTCaYCJIdTp0e0J3MIZCI3dTFT2ScECIMnZICTdGS2NFSTJ0bEpYSmCIYSCGSnIIbFCXYXpGIIdZC0NSMFpCYTCoS2JCCX0Ca3p0FjI3ISp0ZTNIb3J6Sm2IZ2TICTdSZTpYYTSab2CCd0dNSTCXYF03IIJIcEdCbnBDSTCacFNGQTCNZnBoICSxZ2SxFnZSZm0CYCNCS2CCM00NZTS2CTS3SSd0aG0SbCISYFxIcSICZmTNS3pYSjS2C2QxInNIaTC0STdZd2CqZ3C3ZTCyYTCaSTTyaDJIa3T4Fm2IIIZZImxIb0BPSIT2QFIGC0NXbIpIFmxINI3ISmCISTYFSmxISmJGIjNIZSp0YCIIcmZIOSNNZ2cxSTcxNGExI3daZI0IFnpIS2ZSCINIZTT4SF2Ga2SxI3daZSp0SCJ3ZFNGCIdIe3STSISaImQIMSdSZ3poCI2oITdIF3CSMF50SFxIFFECFT0CbIFxFFxIcTdCdICNa2B3SScINSYxCETZaF0XF3SaI2pSIndCSTpCSm2IST2CaICIMn0qCFF2Z2pSCT0SZF0xSIxSMINIFTdISECYFmxINSpSYCSISCIXYTCIS2YCa0CIMjITFjI3dGI0ZTdSIEJoSFxaa2FxITdIb350FjJoc2TFZndCbIT4SICOaE2ZbDZIMI0ZSGxaIGIGCIp0MTJFSmpGcFMyZ3COSCSXY30CNICXM00IM3S4F203aTJXaI0SbnB0CIxISTCYaIZIa2oxSjJ4aFIII3CIIGZXCSCIcTSqITNIMIZ2FF2oFFJIcIpIS2BTYjI3c2dFZTJSIIJQSI24d2dGb0J0ZXZaSmCIIIFyNFNISTpCYTCoSSCIIm0aZSS4SmxIIGIGCm0NME3ySm2II32XCX0XIGxFY3CaIITCd0dXZTJISF53SSJCdCJSbCEIYIxacTdFcIpNZTS4S3dCeIJCC3CjZmZpS3SCeTCYcEdFbSC0I30ISIJSITSSbG0DCGxaIE2SaGTNaFITSTd4bFJGITTSbEJaYCJISIYIImI3ZCISFIx3CTJIIjSIZTpCSCI3IIJYbG0IbEpYSmCId2ZGSXdXbGZqYXpIIIdZCG90ZCI0S20ISFExcI0XSTpCSjIIcmIGIm0NbI0SS2dTYSTXC3dXbTJIFTdISSCCe0dNZTJXSIxOaGI6ZnTIMnZSSmIxcSCIFTpISnBQSI24CFZGInNaZCSCCI2oZTCCcENCST25SGx3SGJIITZCaFZSS3CacTCCZTpIbSJISSd4YSZIInNSZICICI5ocTCZCECCZ2C0YFCIaSJZcEZXbIC0ISCaS2ZFImCIaCSPSm2TdT5ICIdIbFCaSjBaISSCcGIIM3pYYFCISFJYaExSMIp2FTCGISp0eINSS3p0S2CIYISyZT0CbGZFY3CaISCqCTN3bICSFmCTa32Ic0pCSIQTSCJIdGSGaIdIbSI2SmpBMIMxInN0Z2BCYTC3ITCXMCZ3MFT4ST0IC2YIImIIbXZ2FjICeF2SCIpIb0B6ICBaQ2dCSnJjZX0IYICaFIpICECIMSJyCTdIST2Ca0CIbCB2CDJZeSCZI39ISF0XSjB3NICGbISCbE5YSmxIM2dZI39XZTpTCF0ISFJGI30IMIpTYCJOZSICZTNIMm05S2dTa2MxC3dIbTCpFm2ob2ZXc2dTZmZXSm2GSE2IcI0SMjSTYFC3dSIIaICSZ3pYITCaYIZ0C3C3ZTJOSTZIISCCMCZIMSCTFFCoaIJCaGICSEpSF3CaSTdCdGpNS2SISI24a2ZCZjCISECXSnpId2TFZmIXZ35CYFdoF2C0eG0XSTJ0ISFIeGNIaGxIMIpxSICoQ2NIC0JXbE5SY3SIIIYyd0NIMDI2SIxoITCIImIaSTpPCICIc2SCbG0TbIpCSmCaSFExSX0XaFZYYmx3c2FISCIjSmxyI3COCTCCFnTIbIJ0SmIxcmNICIpNZnB6SjBaYIMxC0SCbICXSm5CaIdISmIFM324SF5OSIJXeIZFSTC2YjIacTdICIpIaCETSCJTa2d0InJXbICaS3F2SIYxImI3Z2CSFmI2SFJ0dCIXbICZCFdGZ2dFImTIZ3pXSIc2FFZIIXdaZXZCCSdIMSFyeGCSMFpXYTCGSFJYQ30Ia3pCSjIIdSZCaINNbm0CS3CIIFSxC0NXb35aCCJoFISqZ3dOZTS5CTF5IIJCF3TCSIM2SmIxIISIFTd0MXBFSjB3CmSCZ3CPS35pFjNjeIYyeId0MDI0S20ISGJGc0ISMGQTISCISTdFCG0IbGI2SICIYIJGIXdOSIxaSTCIcTC0eEC3S3CxSFxoS2JXdCBIS2B0FCJNeICFSTSSSF0FSIc2b2CII3dXbGZZYXpGeTYyNSNFbE5SSI5OSmJGI30SMIp0YCJGIGZGSmTIb3I2S2CIYIExC0ZCbICXYCI3IIZSIndIZTpxFm53SIJFbITCMGZCSCJ3cTNZdIdNbm0YISZGImSGITTaZCSXY30CFSCqQm9ZMIxXSF5OIGJCFTTSbX02CFCISFI0dG0NZECXSGxod2dCZX0jIEpaSmxICIT6I39CZCTXYFC3aSJYQ3pIbXB3CFCCeINYbIS0MXBISI24IFNGIXdIa2ZXSmxIIICXdDB0SCIYSIxoST2FFnJIMGZTSmx3dSNISTdSZTYTSmpCYSdCSTCOSTpQSm5CIITFC3NCSTpSF2ZGSE2IcI0IMI02Sm23IGIGaISISnACICJ4cmSXS30IbXZCCSSIISYydGIFMSJCFF5OaETyeI0FSTp2STC3S2pIcGxIbSSxSTd4FFIIIXp0IIpXSjNIS2ZIInNIMIZ2SGxoaIJIIn0XS2Z0CDJIZ2CFF39IM2JXSISIZ2dGSXTOIGZXCSSSMTSCNIIXbFS5SIC3YSCXFTBSa3pTFjIIZ35ICE5ISmIFSmpGYSFxCX0FbTJXYCJIISTZCDZ0ZTCCSIx3S2CIIn0SMjA2SjJ3IISIbGIISnBySmCSeIdGSnJ0ZnBoCI2oFSdISmICMDSTFFCIFFJSQm9FSm0DSICadE2FFTdNSmI2SI2Tb2SGInNjZCTIYCIaaIYyeGIjMXBJI3COCTCFQjSIZTpSSjJGZ2ZZCGpIMIpYIIxobTTxbICXbIpZCS0CIIdZITNIMDI0YTSIST2FFm0IZEp0SjIIcTdIFmTSIEJCS3CjMSFxI3dIb3CFYCIIc2SCMSNXbGxISFT5aICZbDCCSI0ZSjICemIGFTpTa2pySIpGaFZICnZIbE5CYCNCYSCCM00OZ2I4I3C3aETyFT0CI0BCYjIISTSZCIdNS3p6SmTINSd0I3djZIZSY3doCIYIImIjM35GCFC3CTJFQTTXI0BTFjIJeIdFCmIISICPSmxoQ2TIInZ3Z2ZOFm24IIdZaINIM3pSYFCaITCIIjNISTp0CEFxS2ZIS35IMF0XSTcxNGQxFnNCbTJIY3CIS2CFcEC3MSpSFS0oIISxI30CSSpZSG23dGISbI0IbSEIS3ZGIFZGFnJ0ZF0CY30Cd2CqQmCSbSCCSF5Ia2SIInJFSTC2CIxZd2CCZTCIb0B6SCJ4F2CIIT00ZSJICSCIaI3ye0dCST5GCTC3aSSCY2dIbXB0YjJZeIpSI35CZ20XIIC3b2TIb0JXa2ZFFmx3STSCeGCFM3pGSFxIITCIcIZISEpGCIxGdIJIaIdNMFpSSjIaYIExIX0FbGxpFjJoSITIaG9XSmZXI3ZCSE2ZNXpISCSTSTd3STdIaISIM2SCSCBaYIZ0S3dFbI0XY30CITdISm9SMIZ0S20ISmJXaIdaS2Z0YFCINTJCdGpSSSpJI3SaC2YxIXp0ZTCXY3dONIZSCIJTSTp2SGx3IISCa0pISEJICSC3Z2dFZTJSbSJSSITxMETxIXT3ZCTYFjBIIITZFmIXbIpYSI5aST2qZT0CMn0ZYCIGd |
词频分析:
发现类似密钥的ISCTFZ023
,再观察flag.txt
文件中有一些不可见信息,结合题目意思,猜测存在snow隐写
参考【HTML中隐写】Snow免安装、网站版,基本使用方法_snow隐写_黑色地带(崛起)的博客-CSDN博客
根据文章输入命令即可解密
写在最后
星盟安全团队纳新!
欢迎师傅们加群(346014666)学习、讨论!