Clarification on conflicting licenses (CC0/CC4/attribution?)

[PSjason]

Please clarify the license, especially whether there is any attribution requirement when the code is used.

As of today,

• CC0 Universal COPYING.txt (https://github.com/mheyman/Isopoh.Cryptography.Argon2/blob/master/COPYING.txt) says it is "CC0 1.0 Universal"
• CC4 Attribution LICENSE (https://github.com/mheyman/Isopoh.Cryptography.Argon2/blob/master/LICENSE) says it is "Creative Commons Attributeion [sic] 4.0 International"
• CC0 Universal The comment for the LICENSE commit on Feb 11, 2020 (https://github.com/mheyman/Isopoh.Cryptography.Argon2/commits/master/LICENSE) does not match the contents: "doc: README update and switch from unlicense to CC0"
• CC4 Attribution README (https://github.com/mheyman/Isopoh.Cryptography.Argon2/blob/master/README.md) says it is "Creative Commons Attribution 4.0 International License".

[mheyman]

License/copying/readme file fixed to public domain. Thanks for the heads up.