# Integrated compressor

**URL:** <https://support.delta.chat/t/integrated-compressor/1128>\
**Category:** Uncategorized\
**Created:** [August 1, 2020, 5:15pm UTC](https://support.delta.chat/t/integrated-compressor/1128 "2020-08-01T17:15:31Z")\
**Posts on this page:** 1\
**Showing post:** 7

<div class="post-metadata">

**Author:** ![link2xt](https://support.delta.chat/user_avatar/support.delta.chat/link2xt/32/1971_2.png) [@link2xt](https://support.delta.chat/u/link2xt)\
**Post date:** [March 2, 2021, 6:25pm UTC](https://support.delta.chat/t/integrated-compressor/1128/7 "2021-03-02T18:25:45Z")

</div>

OpenPGP already compresses the message losslessly before encryption, but after encryption the message is base64-encoded. We can hardly do anything about it, because other encodings for OpenPGP are not standardized. There is a [binary MIME content-transfer-encoding](https://tools.ietf.org/html/rfc3030), but it is not widely supported and can’t be used to re-encode OpenPGP messages: OpenPGP messages are not using base64 Content-Transfer-Encoding, but ASCII-Armoring instead. OpenPGP message is basically a text message starting with `-----BEGIN PGP MESSAGE-----`, not a binary file. On TLS level compression is deprecated for security reasons, because of [BREACH](https://en.wikipedia.org/wiki/BREACH) and similar attacks.

As a result, we end up with gzip compression + 33% base64 overhead.

---

_[View the full topic](https://support.delta.chat/t/integrated-compressor/1128)._