Understanding Public Key Cryptography

Sign: Sender用自己的private key签名后,连同自己的public key,发送出去。Receiver用sender的public key解密 Encrypt: Sender用Receiver的public key加密,发送出去。 Signing Because the private key in a key pair belongs to only one party, any time that it is shown that the private key has been used, it can be concluded that only the owner of that key…

A working intro to Cryptography

1. Symmetric Keys Block Cipher Stream Cipher 1.1 Block Ciphers Operate on blocks of data, typically 16 bytes (16个字母) 8bit = 1 byte 假如不够,就在末尾加.通常第一 byte 是0x80,其后是0x00. Example: ABCDABCDABCDAB 变为 ABCDABCDABCDAB\x80\x00\x00\x00 1.2 Block mode cipher block chaining - CBC counter - CTR cipher…

Android N Encryption之局限

0. Background: file and disk encryption Full Disk Encryption (FDE) systems (like Truecrypt, BitLocker and FileVault) encrypt disks at the level of disk sectors. This is an all-or-nothing approach, since the encryption drivers won’t necessarily have any idea what files those sectors represent. At the same time, FDE is…