====== Encryption ====== Encryption is a body of techniques for concealing a message’s meaning from anyone but the intended recipients. It’s crucial at TL6-8 owing to the prevalence of easily intercepted telecomm technologies. The wars of the first half of the 20th century drove this point home, with encryption (and its defeat) influencing several prominent successes and failures. Encryption takes two basic forms: * A code is a series of prearranged secret meanings; e.g., “One of by land, two if by sea.” * A cipher is a method of transforming data – whether via a simple substitution (e.g., Morse code) or a mathematical algorithm. The strongest ciphers disguise the signal as seemingly random gibberish. A recipient who has the key can “decrypt” the message and extract its information. === Code-Breaking (TL5) === In 1929, Henry L. Stimson – U.S. Secretary of State at the time – quipped, “Gentlemen do not read each other’s mail,” and closed the U.S. State Department’s cryptographic unit (the Black Chamber). Meanwhile, unbeknownst to Stimson, the U.S. Navy and Army were intercepting Japanese traffic. Overseas, Britain and Poland were working like mad to defeat the Enigma machine (see Cipher Machine, p. 211). To break a simple, ad-libbed code or cipher, win a Quick Contest of IQ-5 with its creator. Either party may substitute the Cryptography skill (p. B186). Beating the systems under Encryption Devices and Encryption Standards requires Cryptography, however. At TL5-6, use the rules on p. B186 to crack encryption. This is usually a group effort. Each team member with Cryptography at 17+ adds +1 to the leader’s skill (maximum +4). At TL7-8, breaking mathematical ciphers involves running specialized software on a computer. Ignore the time requirements and skill modifiers on p. B186, which are for manually devised codes. Instead, start with the base time under Encryption Standards, apply Time Spent (p. B346) modifiers for extra time, and add software bonuses as follows: Basic Code-Breaking Program (TL7). Basic equipment for breaking TL7 ciphers. Complexity 3. $10,000. LC2. Basic Code-Breaking Program (TL8). Basic equipment for breaking TL8 ciphers. Complexity 3. $1,000. LC3. Good Code-Breaking Program (TL8). +1 to Cryptography. Complexity 5. $10,000. LC2. Fine Code-Breaking Program (TL8). +2 to Cryptography. Complexity 7. $100,000. LC2. === Encryption Devices (TL5) === The earliest encryption device might have been the Spartan “skytale”: a leather strip wrapped around a staff of a particular diameter. The message was written on the strip down the length of the staff (not following the strip). The strip alone was sent to the recipient, who wrapped it around an identical staff to read the message. == Cipher Wheel (TL5) == Thomas Jefferson devised the cipher wheel while serving as minister to France; similar encryption devices were used during the American Civil War and WWI. It consists of several wooden or brass wheels, with the alphabet randomly inscribed along the edge of each, threaded onto a spindle. The operator rotates the wheels until his message appears on one row, and then moves down a row and copies the “nonsense” letters. To decrypt, the recipient lines up the seemingly random letters and moves up a row to read the message. A cipher wheel lets its user encrypt a message with its creator’s Cryptography skill, typically 16-18. Enciphering or deciphering takes two minutes per line. $100, 1 lb. LC2. == Cipher Machine (TL6) == Hundreds of cipher machines were in use in the 1910s and 1920s. The famous Enigma, first offered for sale at a postal workers’ conference in 1923, was just one of many – although a highly successful example. With modifications, it became Germany’s standard encryption machine throughout WWII. Cipher machines resemble Jefferson’s cipher wheel mated to a keyboard, albeit with many refinements. Their alphanumeric rotors move in a cog-like fashion with each keypress, mixing and matching letters and numbers to generate millions upon millions of ciphered alphabets. Such devices grant basic encryption without digital computer technology. $20,000, 20 lbs. LC2. == Encryption Unit (TL8) == This external adapter contains an encryption chip, a keypad, etc. It snaps onto a communicator or connects to it via cable. Different models exist for fax, computer modem, radio, cell phone, etc. See Encryption Standards for effects. Basic Encryption Unit (TL8). $100, 0.25 lb., XS/6 hrs. LC4. Secure Encryption Unit (TL8). $500, 0.25 lb., XS/6 hrs. LC2. === Encryption Standards (TL6) === Encryption systems that use complex mechanisms or mathematical keys are rated for the Complexity of computer needed to crack them. == Basic Encryption (TL6) == This is defined as the encryption standard that – at its TL – is strong enough to be reasonably secure but not so complex that it slows operations. Basic Encryption (TL6). Calls for a $20,000 cipher machine (see above), and only enciphers text. Attempts to crack it require both manual efforts and specialized electromechanical or vacuum-tube hardware. Base time is 10 years for apparatus equal to a Complexity 1 computer in cost and weight, or a year for tools equivalent to a Complexity 2 computer. LC4. Basic Encryption (TL7). A permanent modification to any telecomm hardware. Defeating it requires at least a week and a Complexity 3 computer running code-breaking software (pp. 210-211). $1,000. LC4. Basic Encryption (TL8). A free modification for most telecomm gear. Beating it requires at least a day and a Complexity 5 computer with suitable software. LC4. == Secure Encryption (TL7) == This system is typical of those used to secure classified government or military information. There may be a delay of 1-2 minutes at TL7, or 1-2 seconds at TL8, as messages are sent or data is processed. Cracking it is effectively impossible before TL9. Practical approaches are suborning a key-holder or discovering a weakness in the system’s mathematical basis. Secure Encryption (TL7). A piece of software, usually on a computer dedicated to the purpose. Complexity 2. $5,000. LC2. Secure Encryption (TL8). A built-in microchip for any telecomm device. If connected externally, see Encryption Unit (above). $500. LC2.