The latest articles, guides, and tutorials on cryptography and data security from Cipher Visualizers.https://laoutaris.cc/https://laoutaris.cc/blog/aria_guide/https://laoutaris.cc/blog/aria_guide/ARIA is South Korea's national block cipher, a close cousin of AES that shares its S-box but mixes bytes with a different, self-inverse diffusion layer. Learn how its alternating rounds, key schedule, and 1/π constants work.Fri, 02 Oct 2026 00:00:00 GMThttps://laoutaris.cc/blog/camellia_guide/https://laoutaris.cc/blog/camellia_guide/Camellia is the cipher that stands next to AES in international standards. Learn how this Japanese Feistel design combines byte S-boxes, a linear mixing layer, and key-dependent FL layers to match AES-level security.Fri, 02 Oct 2026 00:00:00 GMThttps://laoutaris.cc/blog/cast128_guide/https://laoutaris.cc/blog/cast128_guide/CAST-128, also called CAST5, was the default cipher in some versions of PGP and GnuPG. Learn how its three alternating round functions, huge 8x32-bit S-boxes, and key-dependent rotations work, and why its 64-bit block now limits it.Fri, 02 Oct 2026 00:00:00 GMThttps://laoutaris.cc/blog/gost_guide/https://laoutaris.cc/blog/gost_guide/GOST 28147-89 was the Soviet Union's answer to DES. Learn how its 32-round Feistel design works, why the standard left the S-boxes undefined, and how the modern Magma cipher fixed that.Fri, 02 Oct 2026 00:00:00 GMThttps://laoutaris.cc/blog/rc5_rc6_guide/https://laoutaris.cc/blog/rc5_rc6_guide/RC5 and RC6 are built from just three operations: addition, XOR, and rotations whose amounts come from the data itself. Learn how Ron Rivest's flexible RC5 led to RC6, an AES finalist.Fri, 02 Oct 2026 00:00:00 GMThttps://laoutaris.cc/blog/serpent_guide/https://laoutaris.cc/blog/serpent_guide/Serpent finished second in the AES competition, and it was built to be the safest finalist. Learn how 32 rounds of tiny S-boxes and a bitslice design traded speed for one of the largest security margins of any block cipher.Fri, 02 Oct 2026 00:00:00 GMThttps://laoutaris.cc/blog/simon_speck_guide/https://laoutaris.cc/blog/simon_speck_guide/Simon and Speck are two lightweight block ciphers released by the NSA in 2013 for tiny devices. Learn how Simon gets by on AND, rotate, and XOR, how Speck uses add, rotate, and XOR, and why they became some of the most debated ciphers ever published.Fri, 02 Oct 2026 00:00:00 GMThttps://laoutaris.cc/blog/skipjack_guide/https://laoutaris.cc/blog/skipjack_guide/Skipjack was the secret NSA cipher inside the Clipper chip, declassified in 1998. Learn how its 32 rounds of alternating rules work on four 16-bit words, and why its 80-bit key and its history make it a cautionary tale.Fri, 02 Oct 2026 00:00:00 GMThttps://laoutaris.cc/blog/sm4_guide/https://laoutaris.cc/blog/sm4_guide/SM4 is China's national block cipher standard, a 32-round design that updates one 32-bit word at a time. Learn how its byte S-box, rotate-and-XOR mixing, and compact key schedule work, and where the cipher is used.Fri, 02 Oct 2026 00:00:00 GMThttps://laoutaris.cc/blog/tea_xtea_guide/https://laoutaris.cc/blog/tea_xtea_guide/TEA is a block cipher small enough to write in a few lines of code, and XTEA is its repaired successor. Learn how shifts, additions, and XORs make a working cipher, and how a flaw in TEA's key handling led to a famous console hack.Fri, 02 Oct 2026 00:00:00 GMThttps://laoutaris.cc/blog/threefish_guide/https://laoutaris.cc/blog/threefish_guide/Threefish is the tweakable block cipher inside the Skein hash function, a SHA-3 finalist. Learn how it builds a strong cipher from just addition, rotation, and XOR on 64-bit words, with no S-boxes at all.Fri, 02 Oct 2026 00:00:00 GMThttps://laoutaris.cc/blog/des_bruteforce_breaker_guide/https://laoutaris.cc/blog/des_bruteforce_breaker_guide/DES never fell to clever math. It fell to a loop: try a key, encrypt a known block, compare, repeat. This post runs that exact loop against real DES, the same one EFF's Deep Crack ran over all 2⁵⁶ keys in 1998.Sat, 26 Sep 2026 00:00:00 GMThttps://laoutaris.cc/blog/md5_collision_breaker_guide/https://laoutaris.cc/blog/md5_collision_breaker_guide/Every hash function is vulnerable to a generic birthday attack. MD5 is vulnerable to something worse: a real, structural flaw that produces full 128-bit collisions far faster than any generic attack should allow. Both are demonstrated here, live and verified.Sat, 26 Sep 2026 00:00:00 GMThttps://laoutaris.cc/blog/rc4_bias_breaker_guide/https://laoutaris.cc/blog/rc4_bias_breaker_guide/RC4's second keystream byte is zero twice as often as it should be. Encrypt the same secret enough times, under any keys at all, and that one flaw hands the secret's second byte straight to anyone watching the ciphertexts.Sat, 26 Sep 2026 00:00:00 GMThttps://laoutaris.cc/blog/dh_breaker_guide/https://laoutaris.cc/blog/dh_breaker_guide/Diffie-Hellman's security rests on the discrete logarithm problem being hard. For a small prime, it isn't. Baby-step giant-step trades a brute-force search of size p for one of roughly √p, and that's the whole reason real DH needs huge safe primes.Sat, 12 Sep 2026 00:00:00 GMThttps://laoutaris.cc/blog/elgamal_breaker_guide/https://laoutaris.cc/blog/elgamal_breaker_guide/ElGamal's private key is just another discrete logarithm. The same baby-step giant-step technique that breaks Diffie-Hellman over a small prime recovers ElGamal's private key too, and from there decrypts any captured ciphertext directly.Sat, 12 Sep 2026 00:00:00 GMThttps://laoutaris.cc/blog/rsa_hastad_breaker_guide/https://laoutaris.cc/blog/rsa_hastad_breaker_guide/A low public exponent like e=3 is efficient and, by itself, still safe. Broadcast the same message to three recipients using e=3 with no padding, and the Chinese Remainder Theorem recovers it with no private key at all.Sat, 12 Sep 2026 00:00:00 GMThttps://laoutaris.cc/blog/rsa_common_modulus_breaker_guide/https://laoutaris.cc/blog/rsa_common_modulus_breaker_guide/Sharing one RSA modulus across multiple key pairs looks like a harmless shortcut: skip prime generation, reuse n. If the same message ever gets encrypted under two of those keys, no private key is needed to read it back.Fri, 11 Sep 2026 00:00:00 GMThttps://laoutaris.cc/blog/rsa_fermat_breaker_guide/https://laoutaris.cc/blog/rsa_fermat_breaker_guide/RSA's security assumes factoring n back into p and q is infeasible. That assumption quietly breaks if the key generator picks p and q too close together. Fermat's 1643 factoring method recovers them both in seconds.Fri, 11 Sep 2026 00:00:00 GMThttps://laoutaris.cc/blog/rsa_wiener_breaker_guide/https://laoutaris.cc/blog/rsa_wiener_breaker_guide/Small private exponents make RSA decryption and signing faster. Michael Wiener showed in 1990 that a d small enough to help performance is also small enough to recover from the public key alone, via continued fractions.Fri, 11 Sep 2026 00:00:00 GMThttps://laoutaris.cc/blog/autokey_breaker_guide/https://laoutaris.cc/blog/autokey_breaker_guide/The Autokey cipher defeats Kasiski examination and the Index of Coincidence by never repeating its key. But the short priming key that starts everything off is still just a handful of letters, and one wrong guess collapses the entire decryption for you.Sat, 22 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/enigma_bombe_breaker_guide/https://laoutaris.cc/blog/enigma_bombe_breaker_guide/The site's simplified Enigma breaker fixes the rotor order, skips the plugboard, and brute-forces 17,576 positions by statistics. The real Bombe did none of that. It searched rotor order and position too, deduced the plugboard through pure logic, and never scored a single decryption.Sat, 22 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/hill_breaker_guide/https://laoutaris.cc/blog/hill_breaker_guide/Every other breaker on this site attacks ciphertext alone, guessing at a key through brute force or statistical search. The Hill cipher doesn't need any of that. Its encryption is pure linear algebra, so a handful of known plaintext letters is enough to solve for the entire key matrix directly.Sat, 22 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/playfair_breaker_guide/https://laoutaris.cc/blog/playfair_breaker_guide/Playfair defeated single-letter frequency analysis by encrypting pairs of letters through a 5×5 key square. But the same simulated-annealing idea that cracks the substitution cipher still works here too, once you swap in quadgram statistics and a richer set of moves.Sat, 22 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/railfence_breaker_guide/https://laoutaris.cc/blog/railfence_breaker_guide/Every other transposition breaker on this site has to search over orderings. Columnar Transposition alone hides a factorial number of column arrangements behind its key. Rail Fence has no such trapdoor: the entire key is a single small number, so brute force checks every possibility outright.Sat, 22 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/adfgvx-cipher/https://laoutaris.cc/blog/adfgvx-cipher/Learn about ADFGVX, the German WWI field cipher that combined Polybius-square fractionation with columnar transposition. It was considered so strong that French cryptanalyst Georges Painvin needed weeks to break a message that helped stop a 1918 offensive.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/affine_breaker_guide/https://laoutaris.cc/blog/affine_breaker_guide/Learn how to break the Affine cipher by brute-forcing its entire 312-key keyspace and scoring each decryption with a common-word heuristic. It's the same strategy that cracks Caesar, just applied to a slightly bigger lock.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/affine-cipher/https://laoutaris.cc/blog/affine-cipher/Learn about the Affine cipher, a generalization of the Caesar cipher that combines multiplication and addition to create a larger, but still breakable, keyspace.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/atbash-cipher/https://laoutaris.cc/blog/atbash-cipher/Learn about the Atbash cipher, one of the oldest known substitution ciphers, where each letter is mirrored to the opposite end of the alphabet.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/autokey-cipher/https://laoutaris.cc/blog/autokey-cipher/Learn about the Autokey cipher, the Vigenère variant that fixes the repeating-key weakness by folding the plaintext itself into the key stream. That closes the door on Kasiski examination.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/bacons-cipher/https://laoutaris.cc/blog/bacons-cipher/Learn about Bacon's cipher, Francis Bacon's 17th-century biliteral system that hides a secret message not by scrambling it, but by encoding it into which of two typefaces each letter of an innocent-looking cover text uses.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/beaufort_breaker_guide/https://laoutaris.cc/blog/beaufort_breaker_guide/The Beaufort cipher's reciprocal formula (C = K − P instead of Vigenère's C = P + K) looks like it should matter to an attacker. It doesn't: the same Kasiski examination, Index of Coincidence, and chi-squared pipeline that breaks Vigenère breaks Beaufort just as cleanly.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/beaufort-cipher/https://laoutaris.cc/blog/beaufort-cipher/Learn about the Beaufort cipher, a Vigenère variant that flips the subtraction around to become its own inverse. The same formula both encrypts and decrypts.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/bifid-cipher/https://laoutaris.cc/blog/bifid-cipher/Learn about the Bifid cipher, Félix Delastelle's fractionating cipher that scrambles a Polybius square's coordinates across an entire message, defeating single-letter frequency analysis far more thoroughly than plain substitution.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/columnar_breaker_guide/https://laoutaris.cc/blog/columnar_breaker_guide/Columnar transposition doesn't hide letters. It just rearranges them, so frequency analysis finds nothing wrong. Learn the attack that actually works: brute-forcing every column order for each candidate key length, scored by common English substrings.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/columnar-transposition-cipher/https://laoutaris.cc/blog/columnar-transposition-cipher/Learn about the columnar transposition cipher, a classic cipher that scrambles the order of letters instead of replacing them. Learn why combining it with substitution led to some of the toughest hand ciphers ever used.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/enigma_breaker_guide/https://laoutaris.cc/blog/enigma_breaker_guide/The real wartime Enigma resisted brute force because of two unknowns stacked on top of its rotor positions: which three rotors were chosen and in what order, and how the plugboard was wired. Together these push the key space past 10^20. Strip those two unknowns away and only 17,576 rotor positions are left, small enough for a modern computer to brute-force outright.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/enigma-machine/https://laoutaris.cc/blog/enigma-machine/Learn how the Enigma machine worked: the WWII German cipher machine that produced a different substitution alphabet for every single keystroke. Its defeat by Alan Turing and Bletchley Park changed the course of the war.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/four-square-cipher/https://laoutaris.cc/blog/four-square-cipher/Learn about the four-square cipher, a digraph substitution cipher that uses four 5x5 grids to encrypt letter pairs without Playfair's awkward same-row and same-column special cases.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/nihilist-cipher/https://laoutaris.cc/blog/nihilist-cipher/Learn about the Nihilist cipher, the 19th-century Russian revolutionary cipher that turns a Polybius square into a polyalphabetic system by adding coordinate numbers together instead of shifting letters.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/one-time-pad/https://laoutaris.cc/blog/one-time-pad/Learn about the one-time pad, the only cipher in this series that is mathematically proven unbreakable, and why that proof rests on three conditions that are almost impossible to satisfy in practice.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/polybius-square/https://laoutaris.cc/blog/polybius-square/Learn about the Polybius square, the ancient Greek cipher that turns every letter into a pair of coordinates. It became the foundation for tap codes, telegraph ciphers, and the ADFGVX cipher.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/substitution_breaker_guide/https://laoutaris.cc/blog/substitution_breaker_guide/A monoalphabetic substitution key is one arbitrary permutation of 26 letters: 26! of them, far too many to brute force and immune to Kasiski or the Index of Coincidence since there's no repeating key. Here's how frequency analysis and a hill-climbing search crack it anyway.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/substitution-cipher/https://laoutaris.cc/blog/substitution-cipher/Learn about the monoalphabetic substitution cipher, the general family of ciphers that Caesar, Atbash, and Affine are all special cases of, and why its huge keyspace still isn't enough to make it secure.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/two-square-cipher/https://laoutaris.cc/blog/two-square-cipher/Learn about the two-square cipher, a digraph substitution cipher that sits between Playfair's single grid and four-square's four grids: two independently keyed squares, one uniform encryption rule.Fri, 21 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/vigenere_breaker_guide/https://laoutaris.cc/blog/vigenere_breaker_guide/For three centuries the Vigenère cipher was called 'le chiffre indéchiffrable.' Learn the two statistical techniques, Kasiski examination and the Index of Coincidence, that finally broke it, and watch them recover a real key letter by letter.Fri, 14 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/ascon_guide/https://laoutaris.cc/blog/ascon_guide/In August 2025, NIST standardized a cipher small enough to run on a battery-powered sensor and simple enough to fit its whole state in five CPU registers. Learn how Ascon's sponge-based permutation delivers real authenticated encryption at a fraction of AES-GCM's footprint.Wed, 05 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/dilithium_guide/https://laoutaris.cc/blog/dilithium_guide/NIST's primary post-quantum signature standard works by signing, checking your own signature against a size limit, and throwing it away and starting over if it's too big. Learn how 'Fiat-Shamir with Aborts' turns a leaky lattice proof into a secure signature.Wed, 05 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/falcon_guide/https://laoutaris.cc/blog/falcon_guide/Falcon produces the smallest signatures of any NIST post-quantum standard. It does that by solving a problem that broke the leading lattice signature schemes of the late 1990s/early 2000s. Learn the hash-and-sign paradigm, and why the naive version of it is fatally insecure.Wed, 05 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/frodokem_guide/https://laoutaris.cc/blog/frodokem_guide/FrodoKEM deliberately throws away the algebraic structure that makes lattice cryptography fast. It trades performance for a security proof that rests on plain, 'vanilla' Learning With Errors. Learn how it works and why some cryptographers prefer that trade.Wed, 05 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/hqc_guide/https://laoutaris.cc/blog/hqc_guide/In March 2025, NIST picked a second code-based algorithm to back up Kyber. This one hides its noise completely differently from McEliece. Learn how HQC masks a public, unscrambled code with pure algebraic randomness instead.Wed, 05 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/kyber_guide/https://laoutaris.cc/blog/kyber_guide/The key encapsulation mechanism NIST chose to replace RSA and ECDH for general-purpose use. Learn how Kyber hides a noisy linear system inside a polynomial ring to get both lattice-hard security and real-world speed.Wed, 05 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/ntru_guide/https://laoutaris.cc/blog/ntru_guide/Before Kyber, before LWE was even named, NTRU showed that ordinary polynomial multiplication in the right ring could resist quantum attacks. Learn how NTRU hides a fast decryption trick behind a public convolution product.Wed, 05 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/rainbow_guide/https://laoutaris.cc/blog/rainbow_guide/Rainbow signed messages using polynomial equations so tangled that solving them looks impossible. Then, in 2022, someone found a shortcut and broke it in a weekend on a laptop. Learn how it worked, and how it fell.Wed, 05 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/saber_guide/https://laoutaris.cc/blog/saber_guide/SABER reached the final round of NIST's post-quantum competition with a trick Kyber doesn't use: instead of adding random noise, it rounds numbers down and lets the rounding error itself do the job. Learn how Learning With Rounding works.Wed, 05 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/sphincs_guide/https://laoutaris.cc/blog/sphincs_guide/Every other post-quantum signature scheme bets on a new hard math problem holding up. SPHINCS+ makes almost no new bet at all: its security rests on nothing but hash functions. Learn how a tree of one-time signatures becomes a full signature scheme.Wed, 05 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/3des_guide/https://laoutaris.cc/blog/3des_guide/DES's 56-bit key became too weak, but the industry didn't design a new cipher. It just ran DES three times. Learn how Triple DES extended the life of the original standard for another two decades.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/aes_gcm_guide/https://laoutaris.cc/blog/aes_gcm_guide/AES-GCM does two jobs at once: it hides your data AND proves nobody tampered with it. Learn how Galois/Counter Mode combines AES with GHASH authentication to become the default choice for TLS, IPsec, and disk encryption.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/aes_guide/https://laoutaris.cc/blog/aes_guide/AES secures nearly everything: HTTPS traffic, encrypted disks, and government secrets alike. Here's how the Rijndael cipher transforms data, round by round.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/argon2_guide/https://laoutaris.cc/blog/argon2_guide/Argon2 won the 2015 Password Hashing Competition by making brute-force attacks expensive in RAM, not just CPU time. That closes off the GPU and ASIC cracking farms that broke older schemes. Here's how memory-hardness works.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/blowfish_guide/https://laoutaris.cc/blog/blowfish_guide/Bruce Schneier designed Blowfish as a free, fast alternative to DES, with a distinctive twist: its own S-boxes are generated from the encryption key itself. Learn how it works and why it's still found in legacy systems today.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/chacha20_poly1305_guide/https://laoutaris.cc/blog/chacha20_poly1305_guide/TLS 1.3's second mandatory cipher suite pairs ChaCha20 encryption with the Poly1305 message authenticator, delivering AES-GCM-equivalent security without needing any special hardware. Here's how the pairing works.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/cmac_guide/https://laoutaris.cc/blog/cmac_guide/What if you already have AES in your system and don't want to bring in a separate hash function just for message authentication? CMAC builds a MAC directly from a block cipher instead.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/des_guide/https://laoutaris.cc/blog/des_guide/The Data Encryption Standard ruled cryptography for over two decades. Learn how its Feistel network works, why its 56-bit key ultimately doomed it, and why it still matters as the foundation for 3DES and AES.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/dsa_guide/https://laoutaris.cc/blog/dsa_guide/DSA was the U.S. government's answer to a simple question: how do you prove a message came from you, without RSA's patent? Learn how the Digital Signature Algorithm works, and why a single reused number sank Sony's PS3 security.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/hkdf_guide/https://laoutaris.cc/blog/hkdf_guide/TLS 1.3 and the Signal Protocol both lean on the same small, elegant primitive to turn a shared secret into however many separate keys they actually need. Here's how HKDF's extract-then-expand design works.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/hmac_guide/https://laoutaris.cc/blog/hmac_guide/A hash alone can't prove a message wasn't tampered with. Anyone can recompute it. HMAC fixes that by mixing in a secret key, becoming one of the most quietly essential building blocks in TLS, SSH, and beyond.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/idea_guide/https://laoutaris.cc/blog/idea_guide/IDEA was one of the first ciphers to mix three completely different mathematical operations within a single round. Learn how this Swiss-designed algorithm became a mainstay of early PGP, and why it eventually gave way to AES.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/mceliece_guide/https://laoutaris.cc/blog/mceliece_guide/McEliece has survived over 45 years of cryptanalysis without ever being broken. It's one of NIST's chosen post-quantum standards. Learn how hiding an error-correcting code behind scrambling matrices creates a public-key system quantum computers can't crack.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/paillier_guide/https://laoutaris.cc/blog/paillier_guide/What if you could add two numbers together without ever decrypting them? Paillier encryption makes that possible. It's the mathematical trick behind private vote tallying and secure multi-party computation.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/pbkdf2_guide/https://laoutaris.cc/blog/pbkdf2_guide/For nearly two decades, PBKDF2's answer to password cracking was simple: make every guess expensive by repeating a hash thousands of times. Here's how it works, and why memory-hard successors like Argon2 eventually surpassed it.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/rc4_guide/https://laoutaris.cc/blog/rc4_guide/RC4 was the simplest, fastest cipher of its era. It powered SSL, WEP, and WPA for over a decade before a decade of accumulating bias attacks quietly killed it. Learn how it works and exactly why it's insecure today.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/rsa_guide/https://laoutaris.cc/blog/rsa_guide/RSA made public-key cryptography practical for the world. Here's how it works, why it's secure, and where it's headed as quantum computing looms.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/salsa20_chacha_guide/https://laoutaris.cc/blog/salsa20_chacha_guide/Designed by Daniel J. Bernstein as a fast, secure, RC4-free alternative for software encryption, ChaCha20 now secures TLS 1.3 and WireGuard alike. Learn how its add-rotate-XOR "quarter round" builds a full cipher from pure arithmetic.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/schnorr_guide/https://laoutaris.cc/blog/schnorr_guide/Schnorr signatures are what DSA might have been if a 20-year patent hadn't gotten in the way. Simpler, provably secure, and now at the heart of Bitcoin's Taproot upgrade: here's how they work.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/shake_guide/https://laoutaris.cc/blog/shake_guide/Most hash functions give you a fixed-size output no matter what you ask for. SHAKE breaks that rule: it's a hash function you can ask for any amount of output from, built from the same Keccak sponge as SHA-3.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/twofish_guide/https://laoutaris.cc/blog/twofish_guide/Twofish was Bruce Schneier's answer to Blowfish's biggest weakness, and one of the five finalists in the competition that ultimately chose AES. Learn how its Feistel network, PHT mixing, and key-dependent S-boxes work.Tue, 04 Aug 2026 00:00:00 GMThttps://laoutaris.cc/blog/dh_guide/https://laoutaris.cc/blog/dh_guide/Diffie-Hellman solved cryptography's oldest problem: sharing a secret over a channel anyone can watch. Here's the math, and how it still secures the web.Sun, 27 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/ecc_guide/https://laoutaris.cc/blog/ecc_guide/ECC gets RSA-level security from far smaller keys. Here's the curve math behind it, and why it now powers most of the web.Sun, 27 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/elgamal/https://laoutaris.cc/blog/elgamal/ElGamal turns Diffie-Hellman key exchange into full public-key encryption. Here's how the discrete-log problem protects every message it sends.Sat, 26 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/eddsa/https://laoutaris.cc/blog/eddsa/EdDSA replaced random nonces with deterministic ones, closing off one of ECDSA's worst failure modes. Here's the math behind Ed25519.Fri, 25 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/tls-protocol/https://laoutaris.cc/blog/tls-protocol/Understanding TLS: The Backbone of Secure Internet CommunicationFri, 25 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/signal/https://laoutaris.cc/blog/signal/The Signal Protocol is a modern, open-source cryptographic protocol that provides end-to-end encryption for voice calls, video calls, and instant messaging conversations.Thu, 24 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/pgp-hybrid/https://laoutaris.cc/blog/pgp-hybrid/Understanding Pretty Good Privacy: Hybrid Encryption for Secure Messaging and DataSun, 20 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/blake23-hash/https://laoutaris.cc/blog/blake23-hash/BLAKE2 and BLAKE3 have emerged as the preferred choice for new applications requiring high-performance hashingSat, 19 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/sha1-hash/https://laoutaris.cc/blog/sha1-hash/Secure Hash Algorithm 1 was for years one of the most widely used cryptographic hash functions. Fri, 18 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/sha2-hash/https://laoutaris.cc/blog/sha2-hash/The SHA-2 family of cryptographic hash functions is the gold standard for digital security today.Fri, 18 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/sha3-hash/https://laoutaris.cc/blog/sha3-hash/SHA-3, also known as **Keccak** (pronounced 'ketchak'), is the newest member of the Secure Hash Algorithm family standardized by NIST.Fri, 18 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/md5-hash/https://laoutaris.cc/blog/md5-hash/Ronald Rivest designed MD5 in 1991. By 2004 it was broken. Here's the algorithm, and why real collisions ended its cryptographic career.Wed, 16 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/hill-cipher/https://laoutaris.cc/blog/hill-cipher/Lester Hill brought matrix multiplication to cryptography in 1929. It was the first cipher to encrypt whole blocks of letters at once.Tue, 15 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/playfair-cipher/https://laoutaris.cc/blog/playfair-cipher/The Playfair Cipher: A Complete Educational GuideTue, 15 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/railfence-cipher/https://laoutaris.cc/blog/railfence-cipher/Learn about Mathematical Elegance in Classical CryptographyTue, 15 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/caesar_breaker_guide/https://laoutaris.cc/blog/caesar_breaker_guide/Breaking the Caesar Cipher: A Python Journey from Comprehensive to ConciseMon, 14 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/vigenere-cipher/https://laoutaris.cc/blog/vigenere-cipher/The Vigenère Cipher: A Journey Through History and Modern Applications.Mon, 14 Jul 2025 00:00:00 GMThttps://laoutaris.cc/blog/caesar-cipher/https://laoutaris.cc/blog/caesar-cipher/Learn about one of the simplest and most widely known encryption techniques, the Caesar cipher.Mon, 07 Jul 2025 00:00:00 GMT