Panama (Type 3)

Security Weak Not Recommended | Compression Medium Not Recommended

History Unexistent | RFC Standard Unexistent

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Composition

Compute the CRC32 of the filename AND the CRC with the integer 3 Pick a cipher by index based on the AND above

Filename Ciphers:

Index	Name	Description
0	Whirlpool
1	Tiger
2	Sha1
3	RIPEMD128

Filename is encrypted using the selected cipher The first 4 bytes of the result ciphered filename are AND’ed Pick a cipher by index based on the AND above

Index	Name	Description
0	SHA1
1	RIPEMD128
2	Whirlpool
3	Tiger

Appendix A (Python Representation)

filename_crc = crc32(filename)

filename_ciphers = {
    0: Whirlpool,
    1: Tiger,
    2: Sha1,
    3: RIPEMD128
}

# Make an AND operation on the filename by 4 to act as an index
# And use the index to decide the cipher to use
filename_cipher_index = filename & 4
filename_cipher = filename_ciphers[filename_cipher_index]

ciphered_filename = filename_cipher(filename)

# The panama cipher picker is the first 4 bytes of the ciphered filename
panama_cipher_picker = filename_cipher[4:]

data_ciphers = {
    0: Sha1,
    1: RIPEMD128,
    2: Whirlpool,
    3: Tiger
}

# The panama key IV is the remainder slice of the ciphered filename
ciphered_filename_remainder = filename_cipher[:4]

# And the index to decide the cipher to use is an AND operation by 3
panama_key_cipher_index = ciphered_filename_remainder & 3
panama_key_cipher = filename_ciphers[filename_cipher_index]

# Cipher the remainder slice and get a 32-bytes key named the Panama key
panama_key = panama_key_cipher(ciphered_filename_remainder)

Appendix B (Python Representation)