Tinfoil Hat Linux (THL) was a compact security-focused

Linux distribution A Linux distribution (often abbreviated as distro) is an operating system made from a software collection that includes the Linux kernel and, often, a package management system. Linux users usually obtain their operating system by downloading one ...

designed for high

security Security is protection from, or resilience against, potential harm (or other unwanted coercive change) caused by others, by restraining the freedom of others to act. Beneficiaries (technically referents) of security may be of persons and social ...

developed by The Shmoo Group. The first version (1.000) was released in February 2002. By 2013, it had become a low-priority project. Its image files and source are available in

gzip gzip is a file format and a software application used for file compression and decompression. The program was created by Jean-loup Gailly and Mark Adler as a free software replacement for the compress program used in early Unix systems, and in ...

format. THL can be used on almost any modern PC, as it requires an

Intel 80386 The Intel 386, originally released as 80386 and later renamed i386, is a 32-bit microprocessor introduced in 1985. The first versions had 275,000 transistorsMB of

RAM Ram, ram, or RAM may refer to: Animals * A male sheep * Ram cichlid, a freshwater tropical fish People * Ram (given name) * Ram (surname) * Ram (director) (Ramsubramaniam), an Indian Tamil film director * RAM (musician) (born 1974), Dutch * Ra ...

. The distribution fits on a single HD

floppy disk A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined w ...

. The small footprint provides additional benefits beyond making the system easy to understand and verify- the computer need not even have a

hard drive A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnet ...

, making it easier to "sanitize" the computer after use. The logo of Tinfoil Hat is

Tux Black tie is a semi-formal wear, semi-formal Western dress code for evening events, originating in British and American conventions for clothing, attire in the 19th century. In British English, the dress code is often referred to synecdochically ...

, the Linux mascot, wearing a

tinfoil hat A tin foil hat is a hat made from one or more sheets of aluminium foil (commonly called "tin foil" in the United States and New Zealand), or a piece of conventional headgear lined with foil, often worn in the belief or hope that it shields the br ...

. The Shmoo Group Web site says "It started as a secure, single floppy, bootable Linux distribution for storing PGP keys and then encrypting, signing and wiping files. At some point it became an exercise in over-engineering."

Security features

Tinfoil Hat uses a number of measures to defeat hardware and software surveillance methods like

keystroke logging Keystroke logging, often referred to as keylogging or keyboard capturing, is the action of recording (logging) the keys struck on a keyboard, typically covertly, so that a person using the keyboard is unaware that their actions are being monitored ...

video camera A video camera is an optical instrument that captures videos (as opposed to a movie camera, which records images on film). Video cameras were initially developed for the television industry but have since become widely used for a variety of other ...

, and

TEMPEST Tempest is a synonym for a storm. '' The Tempest'' is a play by William Shakespeare. Tempest or The Tempest may also refer to: Arts and entertainment Films * ''The Tempest'' (1908 film), a British silent film * ''The Tempest'' (1911 film), a ...

: *Encryption —

GNU Privacy Guard GNU Privacy Guard (GnuPG or GPG) is a free-software replacement for Symantec's PGP cryptographic software suite. The software is compliant with RFC 4880, the IETF standards-track specification of OpenPGP. Modern versions of PGP are interoperable ...

(GPG)

public key cryptography Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic alg ...

software is included in THL. *Data retrieval — All temporary files are created on an encrypted ramdisk that is destroyed on shutdown. Even the GPG keyfile information can be stored encrypted on the floppy. *Keystroke monitoring — THL has gpggrid, a wrapper for GPG that lets you use a video game style character entry system instead of typing in your

passphrase A passphrase is a sequence of words or other text used to control access to a computer system, program or data. It is similar to a password in usage, but a passphrase is generally longer for added security. Passphrases are often used to control ...

Keystroke logger Keystroke logging, often referred to as keylogging or keyboard capturing, is the action of recording (logging) the keys struck on a keyboard, typically covertly, so that a person using the keyboard is unaware that their actions are being monitored ...

s get a set of grid points, instead of a passphrase. *Power usage and other

side channel attack In computer security, a side-channel attack is any attack based on extra information that can be gathered because of the fundamental way a computer protocol or algorithm is Implementation#Computer science, implemented, rather than flaws in the d ...

s — Under the Paranoid options, a copy of GPG runs in the background generating keys and encrypting random documents. This makes it harder to determine when real encryption is taking place. *Even reading the screen over the user's shoulder is very hard when Tinfoil Hat is switched to paranoid mode, which sets the screen to a very low contrast.

Applications

An advantage of THL is that it can be used on virtually any modern PC using the

x86 x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was introd ...

processor architecture. For example, one might install it on a computer that is kept in a locked room, not connected to any

network Network, networking and networked may refer to: Science and technology * Network theory, the study of graphs as a representation of relations between discrete objects * Network science, an academic field that studies complex networks Mathematics ...

, and used only for

cryptographically Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adver ...

signing

keys Key or The Key may refer to: Common meanings * Key (cryptography), a piece of information that controls the operation of a cryptography algorithm * Key (lock), device used to control access to places or facilities restricted by a lock * Key (map ...

. It is fairly easy to create the Tinfoil Hat

booting In computing, booting is the process of starting a computer as initiated via hardware such as a button or by a software command. After it is switched on, a computer's central processing unit (CPU) has no software in its main memory, so som ...

floppy with

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

. Verifying the

checksum A checksum is a small-sized block of data derived from another block of digital data for the purpose of detecting errors that may have been introduced during its transmission or storage. By themselves, checksums are often used to verify data ...

can be more tricky. The text of the documentation is salted with just a few jokes, which reinforces their humor by the stark contrast with the serious and paranoiac tone of the surrounding text- the very name pokes fun at itself, as Tinfoil Hats are commonly ascribed to paranoiacs as a method of protecting oneself from mind-control waves. Tinfoil Hat Linux requires one to work in a text-only environment in Linux, i.e. starting straight off with a Bourne shell and the editor vi, not a

graphical user interface The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...

. It uses

BusyBox BusyBox is a software suite that provides several Unix utilities in a single executable file. It runs in a variety of POSIX environments such as Linux, Android, and FreeBSD, although many of the tools it provides are designed to work with in ...

instead of the normal

util-linux is a standard package distributed by the Linux Kernel Organization for use as part of the Linux operating system. A fork, (with meaning "next generation"), was created when development stalled, but has been renamed back to , and is the offic ...

, the

GNU coreutils The GNU Core Utilities or coreutils is a package of GNU software containing implementations for many of the basic tools, such as cat, ls, and rm, which are used on Unix-like operating systems. In September 2002, the ''GNU coreutils'' were cr ...

(formerly known as fileutils, shellutils and textutils) and other common

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...

tools. Tinfoil Hat also offers the

GNU nano GNU nano is a text editor for Unix-like computing systems or operating environments using a command line interface. It emulates the Pico text editor, part of the Pine email client, and also provides additional functionality. Unlike Pico, nano is ...

text editor.

References

External links

Official website

Evilmutant.com article about Tinfoil Hat Linux, with screenshots

Another evilmutant.com article giving links to other media which picked up the previous article
{{Linux-distro Cryptographic software Floppy-based Linux distributions Floppy disk-based operating systems RPM-based Linux distributions Linux distributions

Security features

Applications

See also

References

External links