Carlo Strub

How to store 50000 mails in 10MB to fight Spammers

5 minute read Published:

How to defend against junk mail in modern times

For those who do not allow their mails being read by a large cloud provider, fighting junk mail is an endless task. And, many people developed various – sometimes really clever – techniques to mitigate it. Though, current spam filters are typically time-consuming to configure, consume immense resources (or deliberatly do not use all available information), and are complex in maintenance.

This text is about Sisyphus, a novel filter that automatically learns all (!) your mails’ content to effectively fight off junk, is easy to deploy (one binary), and just needs one line of config, the location of your mail directory.

Harddisk Encryption with Geli

4 minute read Published:

How to encrypt a volume with Geli on FreeBSD and ZFS.

This is a tutorial to guide you through the setup of a fully encrypted laptop with FreeBSD, Geli, and a separate boot/key flash drive.

Holiday Checklist

3 minute read Published:

Useful things to think about when going on vacation

Here are some items to be considered before going on vacation. Winter and Sommer stuff is mixed. If I missed an item, please leave a comment below.


1 minute read Published:

Bapu VM manager

Bapu provides a graphical interface to manage your virtual machines on Gandi.

A General and Intuitive Envelope Theorem (2017, with A. Clausen)

1 minute read Published:

Research paper on dynamic optimization
Previous envelope theorems establish differentiability of value functions. Our techniques apply to all functions whose derivatives appear in first-order conditions. We derive first-order conditions involving the derivatives of (i) the Stackelberg follower’s policy in a Stackelberg leader’s problem, and (ii) a borrower’s value function and default cut-off policy function in an unsecured credit economy. Our techniques also accommodate optimization problems involving discrete choices, infinite horizon stochastic dynamic programming, and Inada conditions.