# crypto101/book

Crypto 101, the introductory book on cryptography.

Repository: https://github.com/crypto101/book
Canonical: https://ross.abutalabs.com/products/crypto101-book
Homepage: https://www.crypto101.io/
Language: Python
License: NOASSERTION
License Family: other
Last push: 2023-09-04T19:44:41+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 4632, "days_push": 1094, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3765, forks 227 (observed 2026-08-28T04:08:18.027555+00:00)

## What it is
Crypto 101 is a free, open-source introductory book on cryptography aimed at programmers, covering ciphers, hash functions, MACs, public-key encryption, and TLS. The repository contains the Sphinx source used to build the book in PDF, EPUB, and other formats.

## Use cases
- learn cryptography from scratch
- understand how SSL/TLS works
- learn how common crypto flaws are exploited
- find a free cryptography book in PDF or EPUB
- teach an introductory cryptography course
- practice breaking weak cryptographic implementations

## When to choose
- you want a free, beginner-friendly introduction to cryptography
- you learn best by exploiting real crypto flaws in code
- you need DRM-free material in multiple ebook formats

## When to avoid
- you need a rigorous mathematical treatment of cryptography
- you want a maintained reference for the latest post-quantum schemes
- you need hands-on software rather than reading material

## Facets
- artifact type: learning-resource
- maturity: maintenance
- function: cryptography, security, documentation
- domain: security, education, tutorials
- platform: cross-platform
- tags: book, cryptography, introductory, free, pdf, epub, security-education

## Member repositories
- crypto101/book (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:18.027555+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:28:36.230171+00:00, confidence not recorded.
  - readme: https://github.com/crypto101/book (fetched 2026-08-28T04:08:18.027555+00:00, sha 8c87981355db)
  - homepage: https://www.crypto101.io/ (fetched 2026-08-29T09:22:44.498120+00:00, sha 90c559149971)
- Data as of 2026-08-30T08:39:29.467469+00:00.