diff --git a/systems/configuration/configuration-domain/BUILD.bazel b/systems/configuration/configuration-domain/BUILD.bazel
index ebccba16..655086cf 100644
--- a/systems/configuration/configuration-domain/BUILD.bazel
+++ b/systems/configuration/configuration-domain/BUILD.bazel
@@ -17,5 +17,14 @@ kt_jvm_test(
     javac_opts = "//:javac_options",
     kotlinc_opts = "//:kotlinc_options",
     test_class = "hs.kr.entrydsm.configuration.domain.ConfigurationDomainModuleTest",
-    deps = MODULE_DEPS + TEST_DEPS,
+    deps = MODULE_DEPS + TEST_DEPS + [":main"],
+)
+
+kt_jvm_test(
+    name = "document_test",
+    srcs = glob(["src/test/kotlin/**/*.kt"]),
+    javac_opts = "//:javac_options",
+    kotlinc_opts = "//:kotlinc_options",
+    test_class = "hs.kr.entrydsm.configuration.domain.document.DocumentDomainTest",
+    deps = MODULE_DEPS + TEST_DEPS + [":main"],
 )
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/DownloadUrl.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/DownloadUrl.kt
new file mode 100644
index 00000000..011d7462
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/DownloadUrl.kt
@@ -0,0 +1,7 @@
+package hs.kr.entrydsm.configuration.domain.document
+
+data class DownloadUrl(
+    val fileName: String,
+    val downloadUrl: String,
+    val expiresIn: Long,
+)
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/FileCategory.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/FileCategory.kt
new file mode 100644
index 00000000..d76abe92
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/FileCategory.kt
@@ -0,0 +1,25 @@
+package hs.kr.entrydsm.configuration.domain.document
+
+private const val MAX_DOCUMENT_SIZE_BYTES = 10L * 1024 * 1024
+private const val MAX_PHOTO_SIZE_BYTES = 5L * 1024 * 1024
+private const val MAX_ATTACHMENT_SIZE_BYTES = 20L * 1024 * 1024
+
+enum class FileCategory(
+    val prefix: String,
+    val allowedExtensions: Set<FileExtension>,
+    val maxSizeBytes: Long,
+) {
+    APPLICATION("application", FileExtension.documentFormats, MAX_DOCUMENT_SIZE_BYTES),
+    ADMISSION_TICKET("admission-ticket", FileExtension.documentFormats, MAX_DOCUMENT_SIZE_BYTES),
+    APPLICANT_LIST("applicant-list", setOf(FileExtension.XLSX), MAX_DOCUMENT_SIZE_BYTES),
+    PHOTO("photo", FileExtension.imageFormats, MAX_PHOTO_SIZE_BYTES),
+    ATTACHMENT("attachment", FileExtension.attachmentFormats, MAX_ATTACHMENT_SIZE_BYTES),
+    GUIDELINE("guideline", FileExtension.attachmentFormats, MAX_ATTACHMENT_SIZE_BYTES),
+    ;
+
+    fun supports(extension: FileExtension): Boolean = extension in allowedExtensions
+
+    fun exceedsMaxSize(sizeBytes: Long): Boolean = sizeBytes > maxSizeBytes
+
+    fun objectKeyOf(fileName: String): String = "$prefix/${FileNaming.requireSafeFileName(fileName)}"
+}
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/FileDocument.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/FileDocument.kt
new file mode 100644
index 00000000..8a93cc01
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/FileDocument.kt
@@ -0,0 +1,17 @@
+package hs.kr.entrydsm.configuration.domain.document
+
+import java.time.Instant
+
+data class FileDocument(
+    val id: Long? = null,
+    val originalName: String,
+    val objectKey: String,
+    val bucket: String,
+    val contentType: String,
+    val sizeBytes: Long,
+    val checksum: String,
+    val createdAt: Instant? = null,
+) {
+    val fileName: String
+        get() = objectKey.substringAfterLast('/')
+}
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/FileExtension.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/FileExtension.kt
new file mode 100644
index 00000000..2482f9b1
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/FileExtension.kt
@@ -0,0 +1,35 @@
+package hs.kr.entrydsm.configuration.domain.document
+
+enum class FileExtension(
+    val value: String,
+    val contentType: String,
+    private val aliases: Set<String> = emptySet(),
+) {
+    PDF("pdf", "application/pdf"),
+    HWP("hwp", "application/x-hwp"),
+    XLSX("xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"),
+    DOCX("docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"),
+    JPG("jpg", "image/jpeg", setOf("jpeg")),
+    PNG("png", "image/png"),
+    WEBP("webp", "image/webp"),
+    ;
+
+    companion object {
+        val documentFormats = setOf(PDF, HWP)
+
+        val imageFormats = setOf(JPG, PNG, WEBP)
+
+        val attachmentFormats = documentFormats + imageFormats + setOf(XLSX, DOCX)
+
+        fun fromFileName(fileName: String): FileExtension? {
+            val extension = fileName.substringAfterLast('.', "")
+            if (extension.isEmpty()) return null
+            return fromExtension(extension)
+        }
+
+        fun fromExtension(extension: String): FileExtension? {
+            val normalized = extension.removePrefix(".").lowercase()
+            return entries.firstOrNull { it.value == normalized || normalized in it.aliases }
+        }
+    }
+}
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/FileNaming.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/FileNaming.kt
new file mode 100644
index 00000000..6657c6b0
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/FileNaming.kt
@@ -0,0 +1,51 @@
+package hs.kr.entrydsm.configuration.domain.document
+
+import hs.kr.entrydsm.configuration.domain.document.exception.InvalidFileNameException
+import java.time.LocalDate
+import java.time.format.DateTimeFormatter
+import java.util.UUID
+
+private val safeIdentifier = Regex("[A-Za-z0-9_-]+")
+private val unsafeCharacters = Regex("[^A-Za-z0-9._-]")
+private val applicantListDate = DateTimeFormatter.ofPattern("yyyyMMdd")
+
+object FileNaming {
+
+    fun applicationFileName(receiptCode: String, extension: FileExtension): String =
+        "application_${requireIdentifier(receiptCode)}.${extension.value}"
+
+    fun admissionTicketFileName(receiptCode: String, extension: FileExtension): String =
+        "admission_ticket_${requireIdentifier(receiptCode)}.${extension.value}"
+
+    fun applicantListFileName(date: LocalDate): String =
+        "applicants_${applicantListDate.format(date)}.${FileExtension.XLSX.value}"
+
+    fun photoFileName(extension: FileExtension): String =
+        "photo_${randomToken()}.${extension.value}"
+
+    fun attachmentFileName(originalName: String): String =
+        "${randomToken()}_${sanitizeOriginalName(originalName)}"
+
+    fun requireIdentifier(value: String): String {
+        if (!safeIdentifier.matches(value)) throw InvalidFileNameException(value)
+        return value
+    }
+
+    fun requireSafeFileName(fileName: String): String {
+        if (sanitizeOriginalName(fileName) != fileName) throw InvalidFileNameException(fileName)
+        return fileName
+    }
+
+    fun sanitizeOriginalName(originalName: String): String {
+        val baseName = originalName
+            .substringAfterLast('/')
+            .substringAfterLast('\\')
+            .trim()
+        val sanitized = unsafeCharacters.replace(baseName, "_").trimStart('.')
+        if (sanitized.isEmpty() || sanitized == "_") throw InvalidFileNameException(originalName)
+        return sanitized
+    }
+
+    private fun randomToken(): String =
+        UUID.randomUUID().toString().replace("-", "")
+}
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/StoredObject.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/StoredObject.kt
new file mode 100644
index 00000000..dc443a76
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/StoredObject.kt
@@ -0,0 +1,7 @@
+package hs.kr.entrydsm.configuration.domain.document
+
+data class StoredObject(
+    val bucket: String,
+    val objectKey: String,
+    val checksum: String,
+)
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/command/IssueDownloadUrlCommand.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/command/IssueDownloadUrlCommand.kt
new file mode 100644
index 00000000..e79e30dc
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/command/IssueDownloadUrlCommand.kt
@@ -0,0 +1,8 @@
+package hs.kr.entrydsm.configuration.domain.document.command
+
+import hs.kr.entrydsm.configuration.domain.document.FileCategory
+
+data class IssueDownloadUrlCommand(
+    val category: FileCategory,
+    val fileName: String,
+)
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/command/UploadFileCommand.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/command/UploadFileCommand.kt
new file mode 100644
index 00000000..604d1dbf
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/command/UploadFileCommand.kt
@@ -0,0 +1,10 @@
+package hs.kr.entrydsm.configuration.domain.document.command
+
+import hs.kr.entrydsm.configuration.domain.document.FileCategory
+
+data class UploadFileCommand(
+    val category: FileCategory,
+    val originalName: String,
+    val sizeBytes: Long,
+    val fileName: String? = null,
+)
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/FileDocumentNotFoundException.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/FileDocumentNotFoundException.kt
new file mode 100644
index 00000000..32340a4d
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/FileDocumentNotFoundException.kt
@@ -0,0 +1,4 @@
+package hs.kr.entrydsm.configuration.domain.document.exception
+
+class FileDocumentNotFoundException(objectKey: String) :
+    RuntimeException("File not found: $objectKey")
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/FileTooLargeException.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/FileTooLargeException.kt
new file mode 100644
index 00000000..135db72b
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/FileTooLargeException.kt
@@ -0,0 +1,4 @@
+package hs.kr.entrydsm.configuration.domain.document.exception
+
+class FileTooLargeException(sizeBytes: Long, maxSizeBytes: Long) :
+    RuntimeException("File size $sizeBytes bytes exceeds limit of $maxSizeBytes bytes")
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/InvalidFileFormatException.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/InvalidFileFormatException.kt
new file mode 100644
index 00000000..4a2b262f
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/InvalidFileFormatException.kt
@@ -0,0 +1,9 @@
+package hs.kr.entrydsm.configuration.domain.document.exception
+
+import hs.kr.entrydsm.configuration.domain.document.FileCategory
+
+class InvalidFileFormatException(fileName: String, category: FileCategory) :
+    RuntimeException(
+        "Unsupported file format for ${category.name}: $fileName " +
+            "(allowed: ${category.allowedExtensions.joinToString { it.value }})"
+    )
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/InvalidFileNameException.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/InvalidFileNameException.kt
new file mode 100644
index 00000000..e1a58354
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/InvalidFileNameException.kt
@@ -0,0 +1,4 @@
+package hs.kr.entrydsm.configuration.domain.document.exception
+
+class InvalidFileNameException(fileName: String) :
+    RuntimeException("Invalid file name: $fileName")
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/PresignFailedException.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/PresignFailedException.kt
new file mode 100644
index 00000000..68ff8f41
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/PresignFailedException.kt
@@ -0,0 +1,4 @@
+package hs.kr.entrydsm.configuration.domain.document.exception
+
+class PresignFailedException(objectKey: String, cause: Throwable? = null) :
+    RuntimeException("Failed to issue download URL: $objectKey", cause)
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/StorageUploadFailedException.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/StorageUploadFailedException.kt
new file mode 100644
index 00000000..c49cb5b9
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/exception/StorageUploadFailedException.kt
@@ -0,0 +1,4 @@
+package hs.kr.entrydsm.configuration.domain.document.exception
+
+class StorageUploadFailedException(objectKey: String, cause: Throwable? = null) :
+    RuntimeException("Failed to upload file to storage: $objectKey", cause)
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/in/IssueDownloadUrlUseCase.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/in/IssueDownloadUrlUseCase.kt
new file mode 100644
index 00000000..91b99443
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/in/IssueDownloadUrlUseCase.kt
@@ -0,0 +1,9 @@
+package hs.kr.entrydsm.configuration.domain.document.port.`in`
+
+import hs.kr.entrydsm.configuration.domain.document.DownloadUrl
+import hs.kr.entrydsm.configuration.domain.document.command.IssueDownloadUrlCommand
+
+interface IssueDownloadUrlUseCase {
+    fun issueByCommand(command: IssueDownloadUrlCommand): DownloadUrl
+    fun issueById(id: Long): DownloadUrl
+}
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/in/ReadFileUseCase.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/in/ReadFileUseCase.kt
new file mode 100644
index 00000000..aaa97840
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/in/ReadFileUseCase.kt
@@ -0,0 +1,10 @@
+package hs.kr.entrydsm.configuration.domain.document.port.`in`
+
+import hs.kr.entrydsm.configuration.domain.document.FileCategory
+import hs.kr.entrydsm.configuration.domain.document.FileDocument
+
+interface ReadFileUseCase {
+    fun findById(id: Long): FileDocument
+    fun findByFileName(category: FileCategory, fileName: String): FileDocument?
+    fun existsById(id: Long): Boolean
+}
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/in/UploadFileUseCase.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/in/UploadFileUseCase.kt
new file mode 100644
index 00000000..ed4bdc4a
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/in/UploadFileUseCase.kt
@@ -0,0 +1,9 @@
+package hs.kr.entrydsm.configuration.domain.document.port.`in`
+
+import hs.kr.entrydsm.configuration.domain.document.FileDocument
+import hs.kr.entrydsm.configuration.domain.document.command.UploadFileCommand
+import java.io.InputStream
+
+interface UploadFileUseCase {
+    fun upload(command: UploadFileCommand, content: InputStream): FileDocument
+}
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/out/FileDocumentRepository.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/out/FileDocumentRepository.kt
new file mode 100644
index 00000000..c3c4b406
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/out/FileDocumentRepository.kt
@@ -0,0 +1,11 @@
+package hs.kr.entrydsm.configuration.domain.document.port.out
+
+import hs.kr.entrydsm.configuration.domain.document.FileDocument
+
+interface FileDocumentRepository {
+    fun save(fileDocument: FileDocument): FileDocument
+    fun findById(id: Long): FileDocument?
+    fun findByObjectKey(objectKey: String): FileDocument?
+    fun existsById(id: Long): Boolean
+    fun deleteByObjectKey(objectKey: String)
+}
diff --git a/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/out/StoragePort.kt b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/out/StoragePort.kt
new file mode 100644
index 00000000..ceed8aac
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/main/kotlin/hs/kr/entrydsm/configuration/domain/document/port/out/StoragePort.kt
@@ -0,0 +1,19 @@
+package hs.kr.entrydsm.configuration.domain.document.port.out
+
+import hs.kr.entrydsm.configuration.domain.document.StoredObject
+import java.io.InputStream
+
+interface StoragePort {
+    fun upload(
+        objectKey: String,
+        contentType: String,
+        sizeBytes: Long,
+        content: InputStream,
+    ): StoredObject
+
+    fun issueDownloadUrl(objectKey: String, expiresInSeconds: Long): String
+
+    fun exists(objectKey: String): Boolean
+
+    fun delete(objectKey: String)
+}
diff --git a/systems/configuration/configuration-domain/src/test/kotlin/hs/kr/entrydsm/configuration/domain/document/DocumentDomainTest.kt b/systems/configuration/configuration-domain/src/test/kotlin/hs/kr/entrydsm/configuration/domain/document/DocumentDomainTest.kt
new file mode 100644
index 00000000..f7068128
--- /dev/null
+++ b/systems/configuration/configuration-domain/src/test/kotlin/hs/kr/entrydsm/configuration/domain/document/DocumentDomainTest.kt
@@ -0,0 +1,105 @@
+package hs.kr.entrydsm.configuration.domain.document
+
+import hs.kr.entrydsm.configuration.domain.document.exception.InvalidFileNameException
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import java.time.LocalDate
+
+class DocumentDomainTest {
+
+    @Test
+    fun `확장자를 대소문자 구분 없이 인식한다`() {
+        assertEquals(FileExtension.PDF, FileExtension.fromFileName("application_1001.PDF"))
+        assertEquals(FileExtension.XLSX, FileExtension.fromExtension(".xlsx"))
+    }
+
+    @Test
+    fun `jpeg는 jpg의 별칭으로 처리한다`() {
+        assertEquals(FileExtension.JPG, FileExtension.fromFileName("photo.jpeg"))
+        assertEquals("image/jpeg", FileExtension.JPG.contentType)
+    }
+
+    @Test
+    fun `확장자가 없으면 인식하지 않는다`() {
+        assertNull(FileExtension.fromFileName("noextension"))
+        assertNull(FileExtension.fromFileName("unknown.exe"))
+    }
+
+    @Test
+    fun `카테고리마다 허용 확장자가 다르다`() {
+        assertTrue(FileCategory.APPLICATION.supports(FileExtension.PDF))
+        assertFalse(FileCategory.APPLICATION.supports(FileExtension.JPG))
+        assertEquals(setOf(FileExtension.XLSX), FileCategory.APPLICANT_LIST.allowedExtensions)
+        assertTrue(FileCategory.PHOTO.supports(FileExtension.WEBP))
+        assertFalse(FileCategory.PHOTO.supports(FileExtension.PDF))
+        assertTrue(FileCategory.ATTACHMENT.supports(FileExtension.DOCX))
+    }
+
+    @Test
+    fun `카테고리별 용량 한도를 넘으면 초과로 판정한다`() {
+        assertFalse(FileCategory.PHOTO.exceedsMaxSize(FileCategory.PHOTO.maxSizeBytes))
+        assertTrue(FileCategory.PHOTO.exceedsMaxSize(FileCategory.PHOTO.maxSizeBytes + 1))
+    }
+
+    @Test
+    fun `object key는 카테고리 prefix를 붙인다`() {
+        assertEquals(
+            "admission-ticket/admission_ticket_1001.pdf",
+            FileCategory.ADMISSION_TICKET.objectKeyOf("admission_ticket_1001.pdf"),
+        )
+    }
+
+    @Test(expected = InvalidFileNameException::class)
+    fun `object key에 상위 경로 참조가 들어오면 거부한다`() {
+        FileCategory.APPLICANT_LIST.objectKeyOf("../../etc/passwd")
+    }
+
+    @Test
+    fun `명세 예시와 같은 파일명을 만든다`() {
+        assertEquals(
+            "application_1001.pdf",
+            FileNaming.applicationFileName("1001", FileExtension.PDF),
+        )
+        assertEquals(
+            "admission_ticket_1001.pdf",
+            FileNaming.admissionTicketFileName("1001", FileExtension.PDF),
+        )
+        assertEquals(
+            "applicants_20260726.xlsx",
+            FileNaming.applicantListFileName(LocalDate.of(2026, 7, 26)),
+        )
+    }
+
+    @Test
+    fun `증명사진과 첨부파일 이름에 랜덤 토큰을 붙인다`() {
+        assertTrue(FileNaming.photoFileName(FileExtension.JPG).matches(Regex("photo_[0-9a-f]{32}\\.jpg")))
+        assertTrue(FileNaming.attachmentFileName("guide.pdf").matches(Regex("[0-9a-f]{32}_guide\\.pdf")))
+    }
+
+    @Test
+    fun `원본 파일명에서 경로를 제거하고 허용 외 문자를 치환한다`() {
+        assertEquals("pas_swd.pdf", FileNaming.sanitizeOriginalName("../../etc/pas swd.pdf"))
+        assertEquals("report.xlsx", FileNaming.sanitizeOriginalName("C:\\temp\\report.xlsx"))
+    }
+
+    @Test(expected = InvalidFileNameException::class)
+    fun `수험번호에 경로 문자가 들어오면 거부한다`() {
+        FileNaming.requireIdentifier("../1001")
+    }
+
+    @Test(expected = InvalidFileNameException::class)
+    fun `다운로드 파일명에 상위 경로 참조가 들어오면 거부한다`() {
+        FileNaming.requireSafeFileName("../../etc/passwd")
+    }
+
+    @Test
+    fun `정상 다운로드 파일명은 그대로 통과시킨다`() {
+        assertEquals(
+            "applicants_20260726.xlsx",
+            FileNaming.requireSafeFileName("applicants_20260726.xlsx"),
+        )
+    }
+}