These tools are designed to help budding cryptanalysts learn the building blocks of cryptography and cryptanalysis. Currently supports monoalphabetic substitution ciphers and polyalphabetic Vigenere ciphers.
yarnornpm install
- Run
yarn analysefollowed by the cipher type -monoorpoly- and the path to the encrypted file (optional - if blank, a sample ciphertext will be used).
yarn analyse mono /path/to/encrypted/file
This will ouput the cipher alphabet with the count and frequency for each letter. With this information, you can easily do frequency analysis on the text to decipher it.
Output:
Ciphertext: `
BT JPX RMLX PCUV AMLX ICVJP IBTWXVR CI M LMT'R PMTN, MTN YVCJX
CDXV MWMBTRJ JPX AMTNGXRJBAH UQCT JPX QGMRJXV CI JPX YMGG CI JPX
HBTW'R QMGMAX; MTN JPX HBTW RMY JPX QMVJ CI JPX PMTN JPMJ YVCJX.
JPXT JPX HBTW'R ACUTJXTMTAX YMR APMTWXN, MTN PBR JPCUWPJR JVCUFGXN PBL,
RC JPMP JPX SCBTJR CI PBR GCBTR YXVX GCCRXN, MTN PBR HTXXR RLCJX CTX
MWMBTRJ MTCJPXV. JPX HBTW AVBXN MGCUN JC FVBTW BT JPX MRJVCGCWXVR, JPX
APMGNXMTR, MTN JPX RCCJPRMEXVR. MTN JPX HBTW RQMHX, MTN RMBN JC JPX YBRX
LXT CI FMFEGCT, YPCRCXDXV RPMGG VXMN JPBR YVBJBTW, MTN RPCY LX JPX
BTJXVQVXJMJBCT JPXVXCI, RPMGG FX AGCJPXN YBJP RAMVGXJ, MTN PMDX M APMBT
CI WCGN MFCUJ PBR TXAH, MTN RPMGG FX JPX JPBVN VUGXV BT JPX HBTWNCL.
JPXT AMLX BT MGG JPX HBTW'R JBRX LXT; FUJ JPXE ACUGN TCJ VXMN JPX YVBJBTW,
TCV LMHX HTCYT JC JPX HBTW JPX BTJXVQVXJMJBCT JPXVXCI. JPXT YMR HBTW
FXGRPMOOMV WVXMJGE JVCUFGXN, MTN PBR ACUTJXTMTAX YMR APMTWXN BT PBL, MTN
PBR GCVNR YXVX MRJCTBRPXN. TCY JPX KUXXT, FE VXMRCT CI JPX YCVNR CI JPX
HBTW MTN PBR GCVNR, AMLX BTJC JPX FMTKUXJ PCURX; MTN JPX KUXXT RQMHX MTN
RMBN, C HBTW, GBDX ICVXDXV; GXJ TCJ JPE JPCUWPJR JVCUFGX JPXX, TCV GXJ JPE
ACUTJXTMTAX FX APMTWXN; JPXVX BR M LMT BT JPE HBTWNCL, BT YPCL BR JPX RQBVBJ
CI JPX PCGE WCNR; MTN BT JPX NMER CI JPE IMJPXV GBWPJ MTN UTNXVRJMTNBTW MTN
YBRNCL, GBHX JPX YBRNCL CI JPX WCNR, YMR ICUTN BT PBL; YPCL JPX HBTW
TXFUAPMNTXOOMV JPE IMJPXV, JPX HBTW, B RME, JPE IMJPXV, LMNX LMRJXV CI JPX
LMWBABMTR, MRJVCGCWXVR, APMGNXMTR, MTN RCCJPRMEXVR; ICVMRLUAP MR MT XZAXGGXTJ
RQBVBJ, MTN HTCYGXNWX, MTN UTNXVRJMTNBTW, BTJXVQVXJBTW CI NVXMLR, MTN RPCYBTW
CI PMVN RXTJXTAXR, MTN NBRRCGDBTW CI NCUFJR, YXVX ICUTN BT JPX RMLX NMTBXG,
YPCL JPX HBTW TMLXN FXGJXRPMOOMV; TCY GXJ NMTBXG FX AMGGXN, MTN PX YBGG RPCY
JPX BTJXVQVXJMJBCT. JPX IBVRJ ACNXYCVN BR CJPXGGC.`
Analysis:
{
A: {
count: 30,
frequency: "2.1%"
},
B: {
count: 89,
frequency: "6.3%"
},
C: {
count: 101,
frequency: "7.1%"
},
D: {
count: 6,
frequency: "0.4%"
},
E: {
count: 15,
frequency: "1%"
},
F: {
count: 18,
frequency: "1.2%"
},
G: {
count: 53,
frequency: "3.7%"
},
H: {
count: 24,
frequency: "1.6%"
},
I: {
count: 28,
frequency: "1.9%"
},
J: {
count: 130,
frequency: "9.2%"
},
K: {
count: 3,
frequency: "0.1%"
},
L: {
count: 28,
frequency: "1.9%"
},
M: {
count: 118,
frequency: "8.3%"
},
N: {
count: 75,
frequency: "5.3%"
},
O: {
count: 6,
frequency: "0.4%"
},
P: {
count: 113,
frequency: "8%"
},
Q: {
count: 12,
frequency: "0.8%"
},
R: {
count: 91,
frequency: "6.4%"
},
S: {
count: 1,
frequency: "0.1"
},
T: {
count: 131,
frequency: "9.2%"
},
U: {
count: 26,
frequency: "1.8%"
},
V: {
count: 68,
frequency: "4.8%"
},
W: {
count: 40,
frequency: "2.8%"
},
X: {
count: 168,
frequency: "11.9%"
},
Y: {
count: 31,
frequency: "2.1%"
},
Z: {
count: 1,
frequency: "0.1"
}
}- Analyse a polyalphabetic cipher:
yarn analyse poly /path/to/encrypted/file
This will ouput the repeated sequences with the count for each and the distances between each instance.
Output:
Ciphertext: `
KQOWEFVJPUJUUNUKGLMEKJINMWUXFQMKJBGWRLFNFGHUDWUUMBSVLPSNCMUEKQ
CTESWREEKOYSSIWCTUAXYOTAPXPLWPNTCGOJBGFQHTDWXIZAYGFFNSXCSEYNCT
SSPNTUJNYTGGWZGRWUUNEJUUQEAPYMEKQHUIDUXFPGUYTSMTFFSHNUOCZGMRUW
EYTRGKMEEDCTVRECFBDJQCUSWVBPNLGOYLSKMTEFVJJTWWMFMWPNMEMTMHRSPX
FSSKFFSTNUOCZGMDOEOYEEKCPJRGPMURSKHFRSEIUEVGOYCWXIZAYGOSAANYDO
EOYJLWUNHAMEBFELXYVLWNOJNSIOFRWUCCESWKVIDGMUCGOCRUWGNMAAFFVNSI
UDEKQHCEUCPFCMPVSUDGAVEMNYMAMVLFMAOYFNTQCUAFVFJNXKLNEIWCWODCCU
LWRIFTWGMUSWOVMATNYBUHTCOCWFYTNMGYTQMKBBNLGFBTWOJFTWGNTEJKNEED
CLDHWTVBUVGFBIJGYYIDGMVRDGMPLSWGJLAGOEEKJOFEKNYNOLRIVRWVUHEIWU
URWGMUTJCDBNKGMBIDGMEEYGUOTDGGQEUJYOTVGGBRUJYS`;
Analysis: [
{
EFVJ: {
count: 2,
distances: [55]
},
NUOC: {
count: 2,
distances: [20]
},
WGMU: {
count: 2,
distances: [30]
}
},
{
WXIZA: {
count: 2,
distances: [38]
}
}
];- There is an additional, optional parameter: keyword length. After having done the basic analysis, you can split the text encrypted with a Vigenere cipher into the number of alphabets corresponding to the guessed keyword length. This example uses a keyword length of 5 (for brevity, only 2 ciphertexts and corresponding frequency analyses are displayed):
yarn analyse /path/to/encrypted/file 5
Output:
Individual ciphertexts:
Text 0:
KFJKKWMWFWSNKSKIAAWGFWYSYSJGWJAKDGMHZWGDEJWLSFWWMSSTZEKGSSVWYAEWMLWSWSDGWASKUMDMMATFXIDWWWTHWMMLWWJDWVJDDSAKKLWIWJKDYDUVU
{
A: {
count: 7,
frequency: "5%"
},
D: {
count: 10,
frequency: "7.4%"
},
E: {
count: 3,
frequency: "1.7%"
},
F: {
count: 5,
frequency: "3.3%"
},
G: {
count: 6,
frequency: "4.1%"
},
H: {
count: 2,
frequency: "0.8%"
},
I: {
count: 3,
frequency: "1.7%"
},
J: {
count: 7,
frequency: "5%"
},
K: {
count: 11,
frequency: "8.3%"
},
L: {
count: 4,
frequency: "2.5%"
},
M: {
count: 9,
frequency: "6.6%"
},
N: {
count: 1,
frequency: "0.8"
},
S: {
count: 13,
frequency: "9.9%"
},
T: {
count: 3,
frequency: "1.7%"
},
U: {
count: 3,
frequency: "1.7%"
},
V: {
count: 3,
frequency: "1.7%"
},
W: {
count: 24,
frequency: "19%"
},
X: {
count: 1,
frequency: "0.8"
},
Y: {
count: 4,
frequency: "2.5%"
},
Z: {
count: 2,
frequency: "0.8%"
}
}
Text 1:
QVUGJUKRGUVCQWOWXPPOQXGXNPNWUUPQUUTNGEKCCQVGKVWPTPKNGOCPKEGXGNOUEXNIUWGOGFIQCPGNVOQVKWCRGONTFGKGOGKCTGGGGWGJNRVWGCGGGGJGJ
{
C: {
count: 8,
frequency: "5.8%"
},
E: {
count: 3,
frequency: "1.7%"
},
F: {
count: 2,
frequency: "0.8%"
},
G: {
count: 26,
frequency: "20.7%"
},
I: {
count: 2,
frequency: "0.8%"
},
J: {
count: 4,
frequency: "2.5%"
},
K: {
count: 8,
frequency: "5.8%"
},
N: {
count: 9,
frequency: "6.6%"
},
O: {
count: 8,
frequency: "5.8%"
},
P: {
count: 8,
frequency: "5.8%"
},
Q: {
count: 7,
frequency: "5%"
},
R: {
count: 3,
frequency: "1.7%"
},
T: {
count: 4,
frequency: "2.5%"
},
U: {
count: 9,
frequency: "6.6%"
},
V: {
count: 7,
frequency: "5%"
},
W: {
count: 8,
frequency: "5.8%"
},
X: {
count: 5,
frequency: "3.3%"
}
}
[...]- Compare ouputted frequencies with standard frequency tables for the English language
- Convert to proper CLI
- Create interactive UI with file upload and written input
- Implement suggested frequency analysis results that can be modified by the user
- Display, based on the above, potential deciphered plaintext