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title: Sources and License Notices

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# Sources and License Notices
[appendix]
[[sources_licenses]]
== Sources and License Notices

This appendix contains attribution and license notices for material included by permission granted via open licenses.

=== Sources

Material was sourced from various public and open-licensed sources:

* https://wiki.ion.radar.tech[ION Lightning Network Wiki]
* https://medium.com/suredbits/lightning-101-what-is-a-lightning-invoice-d527db1a77e6["Lightning 101: What Is a Lightning Invoice?" by Suredbits]
* https://github.com/lightningnetwork/lightning-rfc[Lightning Network In-Progress Specifications GitHub]; Creative Commons Attribution (CC-BY 4.0)
* https://w.wiki/4QCL[Wikipedia page, "Elliptic-curve Diffie–Hellman"]
* https://w.wiki/4QCX[Wikipedia page, "Digital signature"]
* https://w.wiki/4QCb[Wikipedia page, "Cryptographic hash function"]
* https://w.wiki/4QCc[Wikipedia page, "Onion routing"]
* https://w.wiki/4QCd[Wikimedia Commons, "Lightning Network Protocol Suite"]
* https://w.wiki/4QCf[Wikimedia Commons, "Introduction to the Lightning Network Protocol and the Basics of Lightning Technology"]

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=== BTCPay Server

BTCPay Server https://github.com/btcpayserver/btcpayserver-media[logo, screenshots, and other images] used with permission under the https://github.com/btcpayserver/btcpayserver-media/blob/master/LICENSE[MIT License]:

[quote]
____
MIT License

Copyright (c) 2018 BTCPay Server

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS," WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
____

=== Lamassu Industries AG

Images of the https://lamassu.is/product/gaia[_Gaia_ Bitcoin ATM] seen in <<bitcoin-atm>> are used with permission of Lamassu Industries AG. The use of these images is not an endorsement of the product or company, but are provided as a visual example of a Bitcoin ATM.
