Operation method and electronic device for generating and using filename metadata including encrypted case insensitive filename
An electronic device in an example embodiment may include a communication interface configured to receive an original file, a memory, and a processor. The processor may generate bit information corresponding to uppercase and lowercase letters included in a filename of the original file. The processor may generate a case insensitive (CI) filename in which the filename of the original file is expressed by characters of a first type. The processor may encrypt the CI filename and may calculate a first hash value corresponding to the encrypted CI filename. The processor may record filename metadata including at least one of the encrypted CI filename, a length of the encrypted CI filename, the first hash value, and the bit information, in the memory. The processor may search for a target file to be found based on the filename metadata.
1 . An electronic device comprising:
communication interface, comprising communication circuitry, configured to receive data;
memory; and
at least one processor comprising processing circuitry and operably connected to the communication circuitry and the memory, the at least one processor, individually and/or collectively, configured to:
receive an original file from another device using the communication interface,
based on receiving the original file, store the original file in the memory and generate bit information corresponding to uppercase and lowercase letters comprised in a filename of the original file by allocating a first bit value in correspondence to a position of an uppercase letter comprised in the filename of the original file and allocating a second bit value in correspondence to a position of a lowercase letter comprised in the filename of the original file,
generate a case insensitive (CI) filename in which the filename of the original file is expressed by at least characters of a first type,
encrypt the CI filename,
calculate a first hash value corresponding to the encrypted CI filename,
record filename metadata comprising the encrypted CI filename, a length of the encrypted CI filename, the first hash value, and the bit information, in the memory, and
in response to a request for a target file:
generate a second CI filename in which a filename of the target file is expressed by the characters of the first type,
calculate a second hash value corresponding to an encryption of the second CI filename, and
search for the target file by comparing the second hash value with the first hash value included in the filename metadata stored in the memory.
2 . The electronic device of claim 1 , wherein the encryption of the CI filename includes using block encryption and/or stream encryption.
3 . The electronic device of claim 1 , wherein the characters of the first type comprise at least one of uppercase and lowercase letters.
4 . The electronic device of claim 1 , wherein the at least one processor configured to:
record the filename metadata in a different metadata area in the memory based on an attribute of the filename metadata, and/or
store the filename metadata in a same metadata area in the memory.
5 . The electronic device of claim 1 , wherein the at least one processor configured to:
in the filename metadata, record the encrypted CI filename, the length of the encrypted CI filename, and the first hash value in a directory entry area of the original file, and
in the filename metadata, separately record the bit information in a space for storing a file attribute of the original file and/or an extra attributes space.
6 . The electronic device of claim 1 , wherein the at least one processor configured to:
perform a first comparison whether the first hash value coincides with the second hash value, and
search for the target file based on a result of the first comparison.
7 . The electronic device of claim 6 , wherein the at least one processor configured to, when the result of the first comparison coincides, perform a second comparison whether filename lengths and character strings of the encrypted CI filename recorded in the memory and the encrypted second CI filename coincide with each other, and search for the target file based on a result of the second comparison.
8 . The electronic device of claim 7 , wherein the at least one processor configured to:
when the result of the second comparison coincides, reconstruct the filename of the original file, and
when the result of the second comparison does not coincide, iteratively compare whether hash values corresponding to remaining filenames stored in the memory coincide with the second hash value.
9 . The electronic device of claim 8 , wherein, when the result of the second comparison coincides, at least one processor configured to, based on the bit information, reconstruct the filename of the original file by converting a character of the CI filename corresponding to an order of bits comprised in the bit information into an uppercase letter or a lowercase letter according to the bit information.
10 . The electronic device of claim 8 , wherein, when the result of the second comparison does not coincide, at least one processor configured to, when a third hash value, which is one of the hash values, coincides with the second hash value, perform a third comparison whether filename lengths and character strings of an encrypted third CI filename corresponding to the third hash value and the encrypted second CI filename coincide with each other.
11 . A method of operating an electronic device, the method comprising:
receiving an original file from another device using communication interface comprising communication circuitry;
based on receiving the original file, storing the original file in a memory and generating bit information corresponding to uppercase and lowercase letters comprised in a filename of an original file by allocating a first bit value in correspondence to a position of an uppercase letter comprised in the filename of the original file and allocating a second bit value in correspondence to a position of a lowercase letter comprised in the filename of the original file;
generating a case insensitive (CI) filename in which the filename of the original file is expressed at least by characters of a first type;
encrypting the CI filename;
calculating a first hash value corresponding to the encrypted CI filename;
recording filename metadata comprising the encrypted CI filename, a length of the encrypted CI filename, the first hash value, and the bit information, in the memory; and
in response to a request for a target file:
generating a second CI filename in which a filename of the target file is expressed by the characters of the first type;
calculating a second hash value corresponding to an encryption of the second CI filename; and
searching for the target file by comparing the second hash value with the first hash value included in the filename metadata stored in the memory.
12 . The method of claim 11 , wherein the encryption of the CI filename includes using block encryption and/or stream encryption.
13 . The method of claim 11 , wherein the recording of the filename metadata in the memory comprises:
recording the filename metadata in a different metadata area in the memory based on an attribute of the filename metadata; and
storing the filename metadata in a same metadata area in the memory.
14 . The method of claim 11 , further comprising at least one of:
in the filename metadata, recording the encrypted CI filename, the length of the encrypted CI filename, and the first hash value in a directory entry area of the original file; and
in the filename metadata, separately recording the bit information in an i-node space of the original file or an extra attributes space.
15 . The method of claim 11 , wherein the searching for the target file comprises:
performing a first comparison whether the first hash value coincides with the second hash value;
when the result of the first comparison coincides, performing a second comparison whether filename lengths and character strings of the encrypted CI filename recorded in the memory and the encrypted second CI filename coincide with each other;
when a result of the second comparison coincides, based on the bit information, reconstructing the filename of the original file by converting a character of the CI filename corresponding to an order of bits comprised in the bit information into an uppercase letter or a lowercase letter according to the bit information; and
when the result of the second comparison does not coincide, iteratively comparing whether hash values corresponding to remaining filenames stored in the memory coincide with the second hash value.