Documentation

ZIP Extractor Encryption (ZEE) uses ZIP compression method 91, officially assigned to ZEE by PKWARE, for a family of password-based encryption suites, specified and maintained by Visware LLC. Its first suite, ZEE-1, encrypts and authenticates every file with AES-256 and HMAC-SHA-256, derives independent keys for each file from a single PBKDF2 password derivation, and can also encrypt the central directory to keep file names and metadata private. Archives keep the ordinary ZIP structure; method 91 identifies ZEE encryption, and extra field 0x9101 identifies the actual compression method. The paired Version 1.0.1 FINAL documents include a practical implementer's guide with a worked archive and the full, normative specification with test vectors.

ZIP Extractor Encryption (ZEE): overview and specification