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encryption-asymmetric

Do public keys HAVE to be used used to encrypt?

My question is: Does the public key in a asymmetric key have to be used to encrypt data or can it go either way (be used to decrypt)?

Solution

  • Public keys can only be used to encrypt data, and private keys can only be used to decrypt data.

    If you could decrypt data using a public key, that defeats the purpose of encryption.

    Imagine you put your public key on your Facebook profile so that people can encrypt emails to you if they wish. If public keys could decrypt, then anyone that viewed your profile would have the key to all your emails (that were encrypted using that key pair).