Posts about security, cryptography, encryption, and cryptographic tools
PGP combines symmetric and asymmetric encryption to achieve both speed and security: Symmetric Encryption: The message itself is encrypted using a random session key with an algorithm like AES-256. This is computationally fast for large files. Asymmetric Encryption: The session key is then encrypted with the recipient’s public key using RSA or ECC. Only the…
Verification: You need the public key to verify digital signatures (e.g., in Bitcoin or TLS). Sharing: Public keys are meant to be shared, while the private key must remain secret. Conversion: Sometimes you need to convert a private key file into a public-only certificate for a web server or blockchain application. System Integration: Many tools…
macOS provides built-in keyboard modifier remapping without third-party software. Open System Settings → Keyboard → Modifier Keys and you can reassign any modifier key globally or per-device. To map the right Option key to Control: Open System Settings Navigate to Keyboard → Modifier Keys Select your keyboard device (important if you use multiple keyboards) Set…
Gmail requires OAuth2 authentication for SMTP access — direct passwords have been disabled entirely. This is the only supported method for sending mail through Gmail in Thunderbird, whether you’re using a personal or Workspace account. OAuth2 Setup Open Thunderbird and go to Account Settings → Outgoing Server (SMTP). Click Add and configure these settings: Server…
RSA (Rivest–Shamir–Adleman) underpins SSH authentication, TLS certificates, code signing, and encryption across most Linux systems. OpenSSL is the standard tool for generating and managing these keys. Verify OpenSSL Installation OpenSSL is bundled with virtually all distributions. Check your version: openssl version If it’s missing: # Ubuntu/Debian sudo apt-get install openssl # RHEL/CentOS/Fedora sudo dnf install…
Thunderbird can leak your LAN IP address in SMTP email headers, even though the mail server itself only sees your public IP. This happens because Thunderbird sends its local IP during the HELO/EHLO handshake with the SMTP server, and that information gets recorded in the email header. For example, you might see: Received: from [192.168.1.2]…
Storage Limitations BIOS uses MBR (Master Boot Record) partitioning, which maxes out at 2.2TB addressable space due to 32-bit LBA limitations. UEFI uses GPT (GUID Partition Table), supporting drives up to 9.4 zettabytes theoretically—practically unlimited for current hardware. If you’re deploying systems with large storage arrays or NVMe drives, UEFI is mandatory. Boot Process UEFI…
SMP (Symmetric Multiprocessing) and NUMA (Non-Uniform Memory Access) represent two fundamentally different approaches to multi-processor system architecture. Understanding the distinction matters because it affects how you tune applications, configure kernel parameters, and optimize workloads. Memory Access Latency In SMP, all processors have equal latency when accessing any memory location. Every CPU communicates with RAM through…
EncFS is a transparent encrypted filesystem that works well on Linux and macOS, but Windows doesn’t support it natively. If you’re migrating from Linux or need EncFS-specific functionality on Windows, you’ll need to either run it in a virtual machine or switch to Windows-native alternatives. Why EncFS Doesn’t Work on Windows EncFS relies on FUSE…
EncFS is a FUSE-based encrypted overlay filesystem that was once popular for transparent file encryption. However, its use on Android has become impractical due to Android’s security architecture. Here’s what you need to know in 2026. Why EncFS Doesn’t Work Well on Android Anymore Android’s evolution has made direct EncFS usage difficult: Scoped Storage (enforced…
When you have a password-protected RSA private key (indicated by the Proc-Type: 4,ENCRYPTED header), you’ll need to decrypt it before using it with most applications. The openssl command handles this straightforwardly. Basic decryption Use openssl rsa to decrypt the key: openssl rsa -in encrypted_key.pem -out decrypted_key.pem You’ll be prompted to enter the password for the…
When should the authors anonymize themselves in a paper submitted to a conference for review? Several general concepts: Peer review is the evaluation of work by one or more people of similar competence to the producers of the work (peers). — Wikipedia Single-blind describes experiments where information that could introduce bias or otherwise skew the…
Filtering RSS feeds lets you reduce noise and focus on content that actually matters. Whether you want to exclude posts mentioning certain topics or only see items matching specific keywords, there are several practical approaches depending on your setup. Using dedicated feed filtering services Feed43 (https://www.feed43.com/) is one of the most reliable web-based tools for…
Xterm doesn’t send Alt key escape sequences by default, which breaks Alt-based keybindings in Vim, Emacs, shell readline, and other applications. Here’s how to fix it across different terminal setups. Xterm Configuration Add this to your ~/.Xresources file: xterm*metaSendsEscape: true Then load the changes and restart xterm: xrdb -merge ~/.Xresources xterm & This tells xterm…
Database commands fall into distinct categories based on what they do. The two most fundamental are DDL (Data Definition Language) and DML (Data Manipulation Language). Understanding the difference is essential for anyone working with databases, from writing migrations to managing production systems. DDL: Data Definition Language DDL statements define and modify the structure of your…
Every LaTeX document requires a basic framework. Here’s the minimum viable structure: \documentclass{article} \usepackage[utf-8]{inputenc} \title{My Document} \author{Author Name} \date{\today} \begin{document} \maketitle \section{Introduction} Your content here. \end{document} Common document classes: article — reports, papers, short documents report — longer documents with chapters book — book-length documents with front/back matter beamer — slide presentations letter — formal…
In MFC applications, pressing ESC or Enter closes a dialog by default. To prevent this, override CDialog::PreTranslateMessage() and intercept these key events before they reach the default handler. Basic Implementation BOOL CResultCollectorDlg::PreTranslateMessage(MSG* pMsg) { if(pMsg->message == WM_KEYDOWN) { switch(pMsg->wParam) { case VK_RETURN: // Enter key return TRUE; case VK_ESCAPE: // ESC key return TRUE; }…