php - cookie加密秘钥

Question

对用户cookie加密的秘钥，既可以有强一致性，还不需读库，求个方法（用户登录时存用户信息，需要一个秘钥，求这个秘钥设计方法）

Answer 1

Then this key can only be spliced ​​by getting timestamps and the like

Answer 2

This is what I do: device number (if there is a client device number) + user account + timestamp + custom characters (to further prevent guessing) to concatenate it. You can also combine it with the md5 algorithm to add a password to the whole