Schryption method and device

Abstract

A schryption of a text message is based on a schryption key for defining one or more aspects of an encryption and/or a decryption of the text message. For an encryption of the text message, the schryption key is derived from a user key in the form of an encryption key (e.g., a secret key or a public key), and the text message in the form of plaintext is encrypted as defined, at least partially, by the schryption key to thereby yield a ciphertext. For a decryption of the text message, the schryption key is derived from user key in the form of a decryption key (e.g., a secret key or a private key), and the text message in the form of a ciphertext is decrypted as defined, at least partially, by the schryption key to thereby yield a plaintext.

1 . A method of ciphering a text message, the method comprising:
 receiving the text message and a user key;   deriving a schryption key from the user key, wherein at least a portion of the schryption key defines at least one aspect of a ciphering of the text message; and   ciphering the text message as defined, at least partially, by the schryption key to thereby yield a ciphered text message.   
   
   
       2 . The method of  claim 1 , wherein the text message is a plaintext that is encrypted as defined, at least partially, by the schryption key to thereby yield a ciphertext. 
   
   
       3 . The method of  claim 1 , wherein the text message is a ciphertext that is decrypted as defined, at least partially, by the schryption key to thereby yield a plaintext. 
   
   
       4 . The method of  claim 1 , wherein the schryption key includes at least one of:
 a first control segment for specifying a cipher function to be executed during the ciphering of the text message;   a second control segment for specifying a number of times the function is to be executed during the ciphering of the text message; and   a third control segment for specifying a number of bits of the text message to be processed by the cipher function during the ciphering of the text message.   
   
   
       5 . The method of  claim 1 , further comprising:
 deriving a parameter key from the user key, wherein the parameter key serves as a cipher parameter during the ciphering of the text message.   
   
   
       6 . The method of  claim 1 , further comprising:
 deriving a dummy key from the user key, wherein the dummy key is incorporated into the ciphered text message.   
   
   
       7 . The method of  claim 1 , wherein deriving the schryption key from the use key includes:
 generating a master key as a function of at least the user key and a base key; and   extracting the schryption key from the master key.   
   
   
       8 . A method of encrypting a text message, the method comprising:
 receiving a text message and a secret key;   converting the text message into at least one text message block;   generating a first master key as a function of the secret key and a base key;   extracting a schryption key and a parameter key from the master key;   ciphering at least one text message block as specified by the schryption key to yield a cipher message block;   determining whether the ciphered text message block leaves any text message blocks un-ciphered;   generating a new master key based on the determination, the new master key generated as a function of the first master, base key and schryption key; and   encrypting the text message based on at least the first master key and new master key.