Effect2: Wording

2019-11-05T00:36:38Z

Wording

Effect2: Despite this area being in the news recently, I've been meaning to do this particular software for a while

2019-11-05T00:34:49Z

Despite this area being in the news recently, I've been meaning to do this particular software for a while

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{{FormatInfo
|formattype=electronic
|subcat=Encryption
|released=2013<ref>https://e-x-a.org/codecrypt/mk_bachelor.pdf</ref>
|extensions={{ext|ccr}}
}}
'''Codecrypt''' (shortened to '''CCR''') is a software tool, and format, that performs "post-quantum" cryptography. It functions like a stripped-down version of [[PGP]]; users have a keyring of their private and other peoples' public keys, and they are able to sign things with their private keys, encrypt things to public keys, etc. It was created by Miroslav Kratochvíl for a bachelor's thesis.<ref>https://e-x-a.org/codecrypt/</ref>

Codecrypt can produce symmetrically- as well as asymmetrically-encrypted files. Its signature system, FMTSeq<ref>Dalit Naor, Amir Shenhav, Avishai Wool, "One-Time Signatures Revisited: Practical Fast Signatures Using Fractal Merkle Tree Traversal", 2006 IEEE 24th Convention of Electrical and Electronics Engineers in Israel, online at https://www.eng.tau.ac.il/~yash/Naor_Shenhav_Wool.pdf</ref><ref>Source → README.md</ref>, requires a limit (by default, 65535, i.e. 2^16-1) on the number of signatures a signing key can make.

== Post-Quantum Cryptography ==
A [[quantum computer]] is a computer, constructed with knowledge recent developments in physics, which is able to solve some problems more efficiently than a "classical" computer. Several classes of problems are in the area of cryptography. In particular, a practical quantum computer would be able to break all presently widely-used public-key cryptography systems. However, practical quantum computers have not yet been developed; there is public research that occasionally makes the news for a development, and presumably a lot of secret government work, but, so far, there is nothing useful that a quantum computer can do that a "classical" one cannot. More information can be found at [[Wikipedia:Post-quantum cryptography]], as well as this wiki's pages on [[quantum computer]]s and [[encryption]].

Codecrypt is one of several pieces of software developed with what is intended to be quantum-computer-safe cryptography, but before quantum computers become an immediate threat. It seems plausible that Codecrypt will only see use during this interim period, especially if some the algorithms it uses are shown to be insecure, and because more popular systems like PGP and [[TLS]] are flexible enough to have sufficiently mature post-quantum encryption algorithms added in, once the threat becomes pressing enough.

== Extensions ==
Codecrypt does not add an extension to files by default, but the documentation uses the extension ".ccr" in examples.

== Identification ==
Codecrypt files are divided into sections, each of which start with the character 's' ([[ASCII]]), a decimal string length, a colon character, and then the binary data of that section.<ref>Source → secncode.cpp → sencode_bytes::encode()</ref> The first section will always be an identifier of the subtype of file, which is a string starting with "CCR-". Files produced by the current version of Codecrypt will therefore start with:
* {{magic|s25:CCR-PUBLIC-KEY-QCMDPC-MCE}} <ref name="s">Source → secncode.cpp → serialization.cpp as of commit 8e608b4d8da122abd0aceb0cb1dfc4faae95a286</ref>:173
* {{magic|s26:CCR-PRIVATE-KEY-QCMDPC-MCE}} <ref name="s" />:199
* {{magic|s22:CCR-PRIVATE-KEY-FMTSEQ}} <ref name="s" />:334
* {{magic|s21:CCR-PUBLIC-KEY-FMTSEQ}} <ref name="s" />:416
* {{magic|s20:CCR-ENCRYPTED-MSG-v2}} <ref name="s" />:451
* {{magic|s17:CCR-SIGNED-MSG-v2}} <ref name="s" />:481
* {{magic|s12:CCR-HASHFILE}} <ref name="s" />:525
* {{magic|s10:CCR-SYMKEY}} <ref name="s" />:583

It can be inferred that either {{magic|s20:CCR-ENCRYPTED-MSG-v1}} and {{magic|s17:CCR-SIGNED-MSG-v1}} or {{magic|s17:CCR-ENCRYPTED-MSG}} and {{magic|s14:CCR-SIGNED-MSG}} also existed at some point.

=== ASCII Armor ===
Like PGP, CCR also has an ASCII-armored format. Codecrypt's ASCII-armored files begin with a line consisting of {{magic|------ccr begin ------}}<ref>Source → envelope.cpp → envelope_read()</ref>

== Links ==
* [https://e-x-a.org/codecrypt/ Website]
* [https://gitea.blesmrt.net/exa/codecrypt Source]
** [https://github.com/exaexa/codecrypt Mirror on GitHub]
* [https://pqcrypto.org/ Post-Quantum Cryptography]

== References ==
<references />

@@ Line 18: / Line 18: @@
 == Identification ==
-Codecrypt files are divided into sections, each of which start with the character 's' ([[ASCII]]), a decimal string length, a colon character, and then the binary data of that section.<ref>Source → secncode.cpp → sencode_bytes::encode()</ref> The first section will always be an identifier of the subtype of file, which is a string starting with "CCR-". Files produced by the current version of Codecrypt will therefore start with:
+Codecrypt files are divided into sections, each of which start with the character 's' ([[ASCII]]), the content length as a decimal string, a colon character, and then the binary data of that section.<ref>Source → secncode.cpp → sencode_bytes::encode()</ref> The first section will always be an identifier of the subtype of file, which is a string starting with "CCR-". Files produced by the current version of Codecrypt will therefore start with:
 * {{magic|s25:CCR-PUBLIC-KEY-QCMDPC-MCE}} <ref name="s">Source → secncode.cpp → serialization.cpp as of commit 8e608b4d8da122abd0aceb0cb1dfc4faae95a286</ref><sup>:173</sup>
 * {{magic|s26:CCR-PRIVATE-KEY-QCMDPC-MCE}} <ref name="s" /><sup>:199</sup>

Codecrypt - Revision history

Effect2: Wording

Effect2: Despite this area being in the news recently, I've been meaning to do this particular software for a while