Něco o "soli" tam je:
http://www.google.com/codesearch/p?hl=en#HPREjo_RR rs/p7zip_4.43/7zip/Crypto/7zAES/7zAES.cpp&l=162

bool CKeyInfo::IsEqualTo(const CKeyInfo &a) const
{
  if (SaltSize != a.SaltSize || NumCyclesPower != a.NumCyclesPower)
    return false;
  for (UInt32 i = 0; i < SaltSize; i++)
    if (Salt[i] != a.Salt[i])
      return false;
  return (Password == a.Password);
}

void CKeyInfo::CalculateDigest()
{
  if (NumCyclesPower == 0x3F)
  {
    UInt32 pos;
    for (pos = 0; pos < SaltSize; pos++)
      Key[pos] = Salt[pos];
    for (UInt32 i = 0; i < Password.GetCapacity() && pos < kKeySize; i++)
      Key[pos++] = Password[i];
    for (; pos < kKeySize; pos++)
      Key[pos] = 0;
  }
  else
  {
    NCrypto::NSha256::CContext sha;
    const UInt64 numRounds = UInt64(1) << (NumCyclesPower);
    Byte temp[8] = { 0,0,0,0,0,0,0,0 };
    for (UInt64 round = 0; round < numRounds; round++)
    {
      sha.Update(Salt, SaltSize);
      sha.Update(Password, Password.GetCapacity());
      sha.Update(temp, 8);
      for (int i = 0; i < 8; i++)
        if (++(temp[i]) != 0)
          break;
    }
    sha.Final(Key);
  }
}