bcrypt

1. A Future-Adaptable Password Scheme

   Original bcrypt paper: Eksblowfish and adaptive cost.

2. OpenBSD crypt(3) bcrypt format

   $2b$ hash string format and cost parameter.

3. bcrypt guidance (OWASP)

   Work factor and recommendations for bcrypt.

4. bcrypt input limit

   72-byte password limit and pre-hashing considerations.

5. Upgrading the work factor

   Raising cost over time.

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.