anchor.diff:  
   === Block Ciphers
   
  -In cryptography, a block cipher is a deterministic algorithm operating on 
  -fixed-length groups of bits, called blocks, with an unvarying transformation 
  +In cryptography, a block cipher is a deterministic algorithm operating on
  +fixed-length groups of bits, called blocks, with an unvarying transformation
   that is specified by a symmetric key.
   
   .This is a list of currently supported block ciphers in buddy
  
positive.code: explanation about the differences with MAC
  link:http://crypto.stackexchange.com/a/5647[here].
  
  *buddy-core* comes with support for: 
  link:https://en.wikipedia.org/wiki/PKCS_1[rsassa-pss],
  link:https://en.wikipedia.org/wiki/PKCS_1[rsassa-pkcs] and 
  link:https://en.wikipedia.org/wiki/Elliptic_Curve_Digital_Signature_Algorithm[ecdsa].
  
  .Example signing string using rsassa-pss+sha256
  
negative.code: | Blowfish          | `:blowfish`
  |========================================
  
  Additionally, for good security, is mandatory to combine a block cipher with
  some cipher mode of operation.
  
  .This is a list of currently supported of cipher mode of operation
  