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kimci86
bkcrack
C++2024–2024
kimci86 / bkcrack

bkcrack

Crack legacy zip encryption with Biham and Kocher's known plaintext attack.

3Distinct people
5Mentions
0Explicit recommenders
2.2KGitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Crack legacy zip encryption with Biham and Kocher's known plaintext attack.

GitHub

Where it is used

No documented product use has been verified yet.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

No other repository is repeatedly linked in the same discussions.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 3:56:07 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by week5 dated mentions

Observed mentions: 2024-07-25 20:47:36 UTC to 2024-10-18 13:54:49 UTC. Weeks start Monday, UTC.

0122024-07-22 00:00:00 UTC to 2024-07-29 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 commentsJul 222024-07-29 00:00:00 UTC to 2024-08-05 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-08-05 00:00:00 UTC to 2024-08-12 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-08-12 00:00:00 UTC to 2024-08-19 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-08-19 00:00:00 UTC to 2024-08-26 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-08-26 00:00:00 UTC to 2024-09-02 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-09-02 00:00:00 UTC to 2024-09-09 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 commentsSep 22024-09-09 00:00:00 UTC to 2024-09-16 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2024-09-16 00:00:00 UTC to 2024-09-23 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-09-23 00:00:00 UTC to 2024-09-30 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-09-30 00:00:00 UTC to 2024-10-07 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-10-07 00:00:00 UTC to 2024-10-14 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-10-14 00:00:00 UTC to 2024-10-21 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 commentsOct 14

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
Jul 222024-07-22 00:00:00 UTC2024-07-29 00:00:00 UTC101
Jul 292024-07-29 00:00:00 UTC2024-08-05 00:00:00 UTC000
Aug 52024-08-05 00:00:00 UTC2024-08-12 00:00:00 UTC000
Aug 122024-08-12 00:00:00 UTC2024-08-19 00:00:00 UTC000
Aug 192024-08-19 00:00:00 UTC2024-08-26 00:00:00 UTC000
Aug 262024-08-26 00:00:00 UTC2024-09-02 00:00:00 UTC000
Sep 22024-09-02 00:00:00 UTC2024-09-09 00:00:00 UTC202
Sep 92024-09-09 00:00:00 UTC2024-09-16 00:00:00 UTC101
Sep 162024-09-16 00:00:00 UTC2024-09-23 00:00:00 UTC000
Sep 232024-09-23 00:00:00 UTC2024-09-30 00:00:00 UTC000
Sep 302024-09-30 00:00:00 UTC2024-10-07 00:00:00 UTC000
Oct 72024-10-07 00:00:00 UTC2024-10-14 00:00:00 UTC000
Oct 142024-10-14 00:00:00 UTC2024-10-21 00:00:00 UTC101

What Hacker News says

5 sources
There's a program called bkcrack (<https://github.com/kimci86/bkcrack>) that can crack password-protected ZIPs. An interesting use case is documented in a blog post where someone (the Cloudflare CTO) uses it to recover some otherwise lost source code for a DOS-era program used in South Africa to record encrypted messages to (audio) tape and play them over payphones. <https://blog.jgc.org/2024/09/cracking-old-zip-file-to-help-o...>
In Cracking an old ZIP file to help open source the ANC's "Vula" secret crypto code
I spent a lot of power trying to reverse the actual password and got this far: PROGRAM PATTERN MAX LENGTH TESTED bkcrack ?p 14 bkcrack ?u?d 16 bkcrack ?u 17 bkcrack ?l 15 bkcrack ?u?l?l?l?l?l?l?l?l?l?l?l?l?l?l?l 16 bkcrack ?u?l?u?l?u?l?u?l?u?l?u?l?u?l?u?l 16 hashcat ?u?l?d 14 The author kindly modified bkcrack based on Tim's fuzzy recollection of what he thought he might have chosen for the password: https://github.com/kimci86/bkcrack/pull/56 and https://github.com/kimci86/bkcrack/pull/126. However, I ran out of time to work on this part and it seemed more important to get the actual code running. Also, in t
Read the rest
he course of things I discovered that Tim used PKZIP inside the BASIC code using a password that used non-printing characters.
In Cracking an old ZIP file to help open source the ANC's "Vula" secret crypto code

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