Looks like it means that the encryption cannot be reverse-engineered: http://help.penzu.com/pro/what-is-one-way-encryption/

> One way encryption is a mathematical function that takes a variable-length input string and converts it into a fixed-length binary sequence.

So, a hash function and not encryption? Got it.

Sarcasm aside, we really need to start using the correct terms.

https://paragonie.com/blog/2015/08/you-wouldnt-base64-a-pass...

    Cryptography
    ||\
    | \`- Hash Functions
    |  `- Secret-Key Cryptography
    |    |\
    |     \`- Secret-Key Encryption
    |      `- Secret-Key Authentication
     \
      \
       `- Public-Key Cryptography
         |\
          \`- Public-Key Encryption
           `- Public-Key Authentication

Hashing is NOT encryption.

"One-way encryption" is a terrible term - they mean "encryption that the encryptor cannot decrypt upon demand."

So, asymmetric cryptography.

If you have good hashing, you can build encryption, though.

And if you have a good block cipher you can build a hash function.

Encryption is a reversible, keyed transformation of a message. If you cannot reverse it, it is not encryption. Calling it encryption just introduces confusion.

I concur.

I thought that was just called encryption.

Right. With decent end-to-end encryption, third parties can't circumvent without compromising devices or software. Systems where providers can secretly push compromised software aren't secure. Obviously. There are many eyes on the GnuPG code, for example. But even with Apple and Facebook, PR and financial consequences for backdoors would arguably be huge. Consider how much global business US providers have already lost, just over suspicion raised by Snowden's stuff.