密码学的目标是使破解系统的成本超过受保护信息的价值。
The goal of cryptography is to make it so that the cost of breaking the system exceeds the value of the information protected.
这是最好的时代，这是最坏的时代。
Every improvement in the circumstances of the society tends either directly or indirectly to raise the real rent of land, to increase the real wealth of the landlord, his power of purchasing the labour, or the produce of the labour of other people.
夢を諦めない限り、道は開ける。