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+/**
+ * @file
+ * Encryption/decryption module documentation file.
+ */
+
+/**
+ * @addtogroup encdec_module Encryption/decryption module
+ * 
+ * The Encryption/decryption module provides encryption/decryption functions. 
+ * One can differtiate between symmetric and asymetric algorithms; the 
+ * symmetric ones are mostly used for message confidentiality and the asymmetric 
+ * ones for key exchange and message integrity.
+ * Some symmetric algorithms provide different block cipher modes, mainly 
+ * Electronic Code Book (ECB) which is used for short (64-bit) messages and 
+ * Cipher Block Chaining (CBC) which provides the randomness needed for longer 
+ * messages. 
+ * Sometimes the same functions are used for encryption and decryption.
+ * The following algorithms are provided:
+ * - Symmetric:
+ *   - AES (see \c aes_crypt_ecb() and\c aes_crypt_cbc()).
+ *   - ARCFOUR (see \c arc4_crypt()).
+ *   - Camellia (see \c camellia_crypt_ecb() and\c camellia_crypt_cbc()).
+ *   - DES/3DES (see \c des_crypt_ecb(),\c des_crypt_cbc(),\c des3_crypt_ecb() 
+ *     and\c des3_crypt_cbc()).
+ *   - XTEA (see \c xtea_crypt_ecb()).
+ * - Asymmetric:
+ *   - Diffie-Hellman-Merkle (see \c dhm_read_public(),\c dhm_make_public() 
+ *     and \c dhm_calc_secret()).
+ *   - RSA (see \c rsa_public() and\c rsa_private()).
+ *
+ * This module provides encryption/decryption which can be used to provide 
+ * secrecy.
+ * It also provides asymmetric key functions which can be used for 
+ * confidentiality, integrity, authentication and non-repudiation. 
+ */