Notes for Computer Information Technology 160
您最多选择25个主题 主题必须以字母或数字开头,可以包含连字符 (-),并且长度不得超过35个字符

November 21



set x |x| > m set A, |A| == 64

ascii -> printable 8-bit clean text

base64 characters are [A-Z a-z 0-9 + /]

= is for padding

Trusted Communications

  • who said it = Authentication
  • can’t be denied = Repudiation
  • message cannot be altered = Integrity

algorithm(message, key) = encrypted message



Public Key Encryption

You can encrypt data with a public key so that it can only be decrypted with a private key

You can sign data with a private key so it can be verified with a public key

When both of these are done you have trusted communication


proof that a public key belongs to a person marked by an authority