Merge 'Cryptography' category into 'Encryption'

[dimssu]

Fixes #2822

The 'Cryptography' and 'Encryption' blog categories were equivalent and redundant. This commit merges them by changing the remaining blog post using 'Cryptography' to use 'Encryption' instead.

✔️ Checklist

• Check for common mistakes:
  • Wrap plain URLs in <> to linkify them (learn more).
  • Use the right level of headings: The page title will use a level 1 headings, so your headings should use level 2 and below.
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• For blog posts:
  • Verify the date and post ordering on the /blog page, especially for multiple posts on the same day. Prefer UTC format, e.g. 2025-12-01T14:00:00Z for Dec 1st, 2025, 2pm UTC.
  • Set the correct author and category. Browse existing ones at https://matrix.org/author/ and https://matrix.org/category/ to match them.
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[HarHarLinks]

What is your reasoning for choosing Encryption as winner?

[dimssu]

What is your reasoning for choosing Encryption as winner?

@HarHarLinks Below are the main factors that influenced the decision to go with "Encryption."

• "Encryption" is more user-friendly than the technical term "Cryptography"
• Content focus: Both posts discuss practical encryption implementations, not cryptographic theory
• Better discoverability: Users searching for "how to secure messages" think "encryption" not "cryptography"
• Matches Matrix's mission: Making secure communications accessible requires accessible terminology
• Semantic accuracy: Posts are about encryption systems (libolm, vodozemac, MLS), not the broader field of cryptography
• Consistency with existing categories: Blog uses outcome-oriented terms like "Security," "Trust & Safety," "Tech"
• User expectations: /category/encryption immediately conveys "secure communications"

[dimssu]

@HarHarLinks Should I take the opposite approach and merge Encryption into Cryptography instead?