System for encrypting data with an error correction code

1. A data encryption method of an Error Correction Code (ECC)-based encryption apparatus, the data encryption method comprising:

converting data to be encrypted using a certain encryption function;

generating a codeword by performing ECC encoding on the converted data;

puncturing a part of the converted data included in the codeword;

repeating at least a part of the punctured codeword,

interleaving the punctured data; and

inserting errors to the interleaved data.

2. The data encryption method of claim 1 , wherein repeating comprises iterating at least one block of the punctured codeword.

3. The data encryption method of claim 1 , wherein generating the codeword comprises encoding the data with a Low Density Parity Check (LDPC) code.

4. The data encryption method of claim 3 , wherein puncturing the part of the converted data included in the codeword comprises puncturing a part of information corresponding to columns having high column weights in a parity check matrix of the LDPC code.

5. An encryption apparatus for encrypting data based on an Error Correction Code (ECC), the encryption apparatus comprising:

a converter that converts data to be encrypted using a certain encryption function;

an encoder that generates a codeword by encoding the converted data with the ECC;

a puncture unit that punctures a part of the converted data included in the codeword;

a repeater that repeats at least a part the punctured codeword generated by the puncture unit,

an interleaver that interleaves the punctured data; and

an error inserter that inserts errors to the interleaved data.

6. The encryption apparatus of claim 5 , wherein the repeater iterates at least one block of the punctured codeword.

7. The encryption apparatus of claim 5 , wherein the encoder encodes the data with a Low Density Parity Check (LDPC) code.

8. The encryption apparatus of claim 7 , wherein the puncture unit punctures a part of information corresponding to columns having high column weights in a parity check matrix of the LDPC code.

9. A data decryption method for decrypting encrypted data including blocks in an Error Correction Code (ECC)-based encryption system, the data decryption method comprising:

de-interleaving the encrypted data;

decoding the de-interleaved data to recover a codeword; and

converting the codeword to recover the encrypted data,

wherein converting comprises treating a punctured block of the encrypted data as an erasure and treating a non-punctured block of the encrypted data as a block including errors.

10. The data decryption method of claim 9 , further comprising:

determining, after de-interleaving, whether any part of the encrypted data is repeated;

configuring 0 bits of a block as first configuration values and 1 bits of the block as second configuration values, when any part of the encrypted data is repeated;

adding the configuration values to corresponding bits at same positions of the block;

determining final values of the corresponding bits by comparing values obtained by adding the configuration values with a predetermined threshold value for individual bits; and

inputting the determined final values as input values of an error correction code decoding process.

11. A decryption apparatus for decrypting encrypted data including blocks in an Error Correction Code (ECC)-based encryption system, the decryption apparatus comprising:

a de-interleaver that de-interleaves the encrypted data;

a decoder that decodes the de-interleaved data to recover a codeword; and

an inverse-converter that converts the codeword to recover the encrypted data,

wherein the decoder treats a punctured block of the encrypted data as an erasure and treats a non-punctured block of the encrypted data as a block including errors.

12. The decryption apparatus of claim 11 , further comprising a decoder input determiner that determines whether the encrypted data output by the de-interleaver is repeated.

13. The decryption apparatus of claim 12 , wherein the decoder input determiner inputs the encrypted data output by the de-interleaver to the decoder, when the encrypted data is not repeated.

14. The decryption apparatus of claim 12 , wherein, when the encrypted data is repeated, the decoder input determiner configures 0 bits of a block as first configuration values and 1 bits of the block as second configuration values, adds the configuration values to corresponding bits at same positions of the block, determines final values of the corresponding bits by comparing values obtained by adding the configuration values with a predetermined threshold value for individual bits, and inputs the determined final values as input values of an error correction code decoding process.