Ciphers

Abwehr hand ciphers were cracked early in the war and SD hand ciphers and Abwehr Enigma ciphers followed.

A disadvantage is that such ciphers are considerably more laborious and error prone than simpler ciphers.

Block ciphers must be used in ciphertext stealing or residual block termination mode to avoid padding, while stream ciphers eliminate this issue by naturally operating on the smallest unit that can be transmitted (usually bytes).

Cryptographic primitives based on symmetric ciphers Symmetric ciphers are commonly used to achieve other cryptographic primitives than just encryption.

Historically, cryptography was split into a dichotomy of codes and ciphers; and coding had its own terminology, analogous to that for ciphers: "encoding, codetext, decoding" and so on.

Just as block ciphers can be used to build hash functions, hash functions can be used to build block ciphers.

Linear feedback shift register-based stream ciphers Binary stream ciphers are often constructed using linear feedback shift registers (LFSRs) because they can be easily implemented in hardware and can be readily analysed mathematically.

Simple ciphers were replaced by polyalphabetic substitution ciphers (such as the Vigenère ) which changed the substitution alphabet for every letter.

Substitution in modern cryptography Substitution ciphers as discussed above, especially the older pencil-and-paper hand ciphers, are no longer in serious use.

Such schemes are known as self-synchronizing stream ciphers, asynchronous stream ciphers or ciphertext autokey (CTAK).

The most commonly deployed GPRS ciphers were publicly broken in 2011. citation The researchers revealed flaws in the commonly used GEA/1 and GEA/2 ciphers and published the open-source "gprsdecode" software for sniffing GPRS networks.

With even a small amount of known or estimated plaintext, simple polyalphabetic substitution ciphers and letter transposition ciphers designed for pen and paper encryption are easy to crack.

As the UK faces an unprecedented threat, a line can be traced back to the founder of computer science and his team’s scramble to intercept enemy ciphers in Hut 8 at Bletchley Park.

The Enigma was the machine use to encrypt German ciphers during the war, and was eventually cracked by a team of code-breakers at Bletchley Park in Milton Keynes.

For years, incels have written posts in ciphers to evade detection by law enforcement, something the Toronto van killer Alek Minassian explained in his April 2018 interview with senior detective Rob Thomas.

Some of the characters are little more than ciphers, but Fefu, the wounded Julia, and the bubbly Emma are most distinct personalities.

These and other easily detectable patterns provided British codebreakers with many valuable cribs, starting points for their attacks into the foe’s ciphers.

The suggestion that an author’s characters are merely ciphers for their own mental state is most frequently levelled at female writers, so I feel compelled to say that none of the characters in my debut novel, The Tyranny of Lost Things, are me.

All such ciphers are easier to break than once believed, as substitution alphabets are repeated for sufficiently large plaintexts.

Another application is to build hash functions from block ciphers.