Anyone can decrypt it using the server's public key.

任何人都可以使用服务器的公钥对其进行解密。

In other words, knowing the public key only lets you encrypt, but not decrypt – it’s asymmetric!

换句话说，知道公钥只能加密，不能解密——这是不对称的！

We have these two files: we have the 25519 and the public key.

我们有这两个文件：25519 和公钥。

The problem is that this public key can actually be used to calculate your secret private key.

但问题在于，获得公钥之后是可以通过数学方法计算私钥的。

In the same way, a digital public key can encrypt something that can only be decrypted with a private key.

同样，数字公钥可以加密只能用私钥解密的东西。

The reverse is possible too: encrypting something with a private key that can be decrypted with a public key.

反过来也是可能的：用可以用公钥解密的私钥加密一些东西。

So, people can encrypt a message using a public key that only the recipient, with their private key, can decrypt.

因此，人们可以使用只有收件人使用他们的私钥才能解密的公钥来加密消息。

So what we have to do is we have to encrypt it before it even leaves Bob's computer, and one of the tricks is, we encrypt it using the public key from Alice.

在Bob的讯息离开电脑前我们就将它加密，窍门之一就是我们使用 Alice电脑上的公钥来加密。

SSH keys just use public key encryption to create a pair of SSH keys, a public key and a private key, and then you can give the server the public part of the key.

SSH 密钥只需使用公钥加密来创建一对 SSH 密钥，即公钥和私钥，然后您可以将密钥的公共部分提供给服务器。

So you copy the public key and then whenever you try to authenticate instead of using your password, it's gonna use the private key to prove to the server that you are actually who you say you are.

因此，您复制公钥，然后每当您尝试进行身份验证而不是使用密码时，它都会使用私钥向服务器证明您确实是您所说的人。