2021-2020 Season Science Olympiad Rules Summary

This table summarizes which types of ciphers are used for which division and events. It also indicates which official rule corresponds to this usage. Blank boxes indicate that the cipher is not used for that division/category of event.

CipherTypeDivision BDivision C
Regional/InvitationalState/NationalRegional/InvitationalState/National
AtBashMonoalphabeticEncode+Decode 
3.f.i
CaesarMonoalphabeticEncode+DecodeEncode+Decode
3.e.i.3.e.i.
Aristocrat
Random, K1, K2
MonoalphabeticDecode+CryptanalysisDecode+Cryptanalysis
3.e.ii (1), 3.e.ii (2)3.e.ii (1), 3.e.ii (2)
Aristocrat MisspelledMonoalphabeticDecode+CryptanalysisDecode+Cryptanalysis
3.e.ii (3), 3.e.ii (4)3.e.ii (3), 3.e.ii (4)
PatristocratMonoalphabeticDecode+CryptanalysisDecode+Cryptanalysis
3.e.ii (5), 3.e.ii (6)3.e.ii (5), 3.e.ii (6)
XenocryptMonoalphabetic LanguageDecode+Cryptanalysis (0 or 1)Decode+Cryptanalysis (1+)Decode+Cryptanalysis (0 or 1)Decode+Cryptanalysis (2+)
3.e.ii (5), 3.e.ii (6), 3.e.vi.3.e.ii (5), 3.e.ii (6), 3.h.ii.3.e.ii (5), 3.e.ii (6), 3.e.vi.3.e.ii (5), 3.e.ii (6), 3.i.ii.
Aristocrat, Patristocrat, Xenocrypt
K3
Monoalphabetic Decode+Cryptanalysis
3.g.i.
Aristocrat, Patristocrat, Xenocrypt
Keyword
Monoalphabetic Keyword
3.g.ii.
Hill 2x2Polyalphabetic Math Encode+DecodeEncode+Decode+Matrix
3.g.iii.3.i.i.
Hill 3x3Polyalphabetic Math  Decode
3.i.i.
AffineMonoalphabetic MathEncode+ DecodeEncode+Decode+CryptanalysisEncode+DecodeEncode+Decode+Cryptanalysis
3.e.iii.3.h.iv.3.e.iii.3.h.iv.
VigenèèrePolyalphabeticEncode+DecodeEncode+Decode+CryptanalysisEncode+DecodeEncode+Decode+Cryptanalysis
3.e.iv.3.h.iii.3.e.iv.3.h.iii.
BaconianSteganographyCryptanalysisCryptanalysis
3.e.v.3.e.v.
MorbitTomogrammicDecodeDecode+CryptanalysisDecodeDecode+Cryptanalysis
3.e.vii.3.h.v.3.e.vii.3.h.v.
PolluxTomogrammicDecodeDecode+CryptanalysisDecodeDecode+Cryptanalysis
3.e.vii.3.h.v.3.e.vii.3.h.v.
PortaPolyalphabetic CryptanalysisEncode+DecodeEncode+Decode+Cryptanalysis
3.h.vi.3.g.iv.3.h.iv.
Railfence
0 Offset
Transposition Cryptanalysis Decode+Cryptanalysis
3.h.vii.3.h.vii.
Railfence
Unknown Offset
Transposition DecodeDecode+Cryptanalysis
3.g.v.3.i.iii.