Markku-Juhani O. Saarinen mjosaarinen

One way for setting up file permissions for Agentic CLI

2026-05-20 Markku-Juhani O. Saarinen

Using Agentic AI (Claude Code, Codex) for coding is great, but running such a creative (and sometimes unpredictable) system with full visibility to your personal files (ssh keys, browser-stored passwords, etc.) is dangerous.

There are various ways of doing sandboxing. Using the standard Linux user separation, access control, and shared group permissions is actually one of the more powerful ones and should be used as a baseline.

Note that to do any of this, you need to be competent enough to use a self-administered Linux system (local root). If you're not comfortable with it, don't use Agentic CLIs.

DRAFT of 2020 May 28 Markku-Juhani O. Saarinen <mjos@pqshield.com>

On RISC-V Logic Optimization for Cryptography

Many cryptographic functions require computation of Boolean functions from n bits to m bits. Sometimes these functions are large enough to have been traditionally implemented with table lookups, but timing side-channel considerations force their implementation in a bit-sliced manner.

Keybase proof

I hereby claim:

I am mjosaarinen on github.
I am mjos (https://keybase.io/mjos) on keybase.
I have a public key whose fingerprint is 143F 245C 066C E2D9 8379 E287 C285 8B1B 5517 1BD5

To claim this, I am signing this object:

	// sumhash0.go
	// 2022-06-18 Markku-Juhani O. saarinen <mjos@mjos.fi>

	// === A sumhash-512 with 110 leading zero bits (from left)

	/*
	input = AA4F827EE71BF78B816E767A24B271AD046A3C52DA8B25EAB2D59A86C8B93F02FB73184B74A5F8F227FD1500000000
	H(x) = 000000000000000000000000000385D978E7FF3D3239DB4F1C357EA40940EAB592F34AEC646DED668859B622341566A838B566490E2AC71DBA89B067E647FC31
	*/

	#!/usr/bin/env python3

	# tslider.py
	# 2021-08-02 Markku-Juhani O. Saarinen <mjos@pqshield.com>
	# Free to play with!

	# === Welch T test sliders (for teaching TVLA statistics)

	# Welch T-Test ("TVLA") Sliders with Python 3 matplotlib. The thick lines
	# are the distributions of averages of N Gaussian variables, which are

	Markku-Juhani O. Saarinen <mjos@pqshield.com>

	Apr 11, 2021, 9:32 PM (2 days ago)

	to Tech-crypto-ext@lists.riscv.org, tech-bitmanip@lists.riscv.org.

	Hello Bitmanip and Krypto,

	A colleague asked: "Why CMOV is not on the constant-time Zkt list -- the Bitmanip specification says that it is helpful for cryptography?" https://github.com/rvkrypto/riscv-zkt-list