Hawkynt

XXencoding

Binary-to-text encoding similar to UUencoding but uses a different character set designed to avoid problematic characters in some communication systems. Alternative encoding method for transmitting binary data over text-based protocols. Educational implementation for learning purposes.

Properties

Property	Value
Category	Encoding Schemes
Sub-category	Mail Encoding
Security status	🎓 Educational Only
Complexity	Beginner
Inventor	Unix Community
Year	1980
Origin	🇺🇸 United States
Source	algorithms/encoding/xxencode.js

Security

Status: 🎓 Educational Only

No vulnerabilities are recorded for this implementation.

Documentation

• XXencode Specification
• UUencoding Alternatives
• Binary Encoding History

References

• Unix Mail Systems
• Text-based Binary Transfer
• Character Set Standards

Test vectors

7 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.

Vector 1 — XXencode empty data test

Source: Educational standard

Field	Value
input	(empty)
expected	(empty)

Vector 2 — Basic 3-byte zero test - XXencode

Source: Educational example

Field	Value
input	000000
expected	2b2b2b2b

Vector 3 — Simple pattern encoding test - XXencode

Source: Educational standard

Field	Value
input	010203
expected	2b453631

Vector 4 — XXencode 1-byte group - eight data bits need exactly two 6-bit symbols

Field	Value
input	4d
expected	4845

Vector 5 — XXencode 2-byte group - sixteen data bits need exactly three 6-bit symbols

Field	Value
input	4d61
expected	484b32

Vector 6 — XXencode trailing NUL regression test - the old decoder stripped trailing zero bytes as if they were padding, so any payload ending in NUL decoded short and could not be re-encoded

Field	Value
input	01020300
expected	2b4536312b2b

Vector 7 — XXencode all-NUL payload regression test - the old decoder returned an empty array for any all-zero payload

Field	Value
input	0000000000
expected	2b2b2b2b2b2b2b

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