diff --git a/libfic/file.go b/libfic/file.go
index 2cd517a2..ebdb7a7d 100644
--- a/libfic/file.go
+++ b/libfic/file.go
@@ -23,6 +23,9 @@ var OptionalDigest bool = false
 // StrongDigest forces the use of BLAKE2b hash in place of SHA1 (or mixed SHA1/BLAKE2b).
 var StrongDigest bool = false
 
+// Set PlainDigest if digest errors should contain the whole calculated hash, to be paste directly into DIGESTS file.
+var PlainDigest bool = false
+
 // EFile represents a challenge file.
 type EFile struct {
 	Id         int64 `json:"id"`
@@ -117,6 +120,16 @@ func (e Exercice) GetFileByPath(path string) (EFile, error) {
 	return f, nil
 }
 
+// minifyHash returns only the begining and the end of the given hash.
+// Use this function to ensure people doesn't fill their file with our calculated hash.
+func minifyHash(hash string) string {
+	if PlainDigest {
+		return hash
+	} else {
+		return hash[0:len(hash)/3] + "..." + hash[len(hash)/2:]
+	}
+}
+
 // checkFileHash checks if the file at the given filePath has the given digest.
 // It also returns the file's size.
 func checkFileHash(filePath string, digest []byte) ([]byte, int64, error) {
@@ -142,20 +155,20 @@ func checkFileHash(filePath string, digest []byte) ([]byte, int64, error) {
 
 		if len(digest) != len(result512) {
 			if len(digest) != len(result160) {
-				return []byte{}, fi.Size(), errors.New("Digests doesn't match: calculated: sha1:" + hex.EncodeToString(result160) + " & blake2b:" + hex.EncodeToString(result512) + " vs. given: " + hex.EncodeToString(digest))
+				return []byte{}, fi.Size(), errors.New("Digests doesn't match: calculated: sha1:" + minifyHash(hex.EncodeToString(result160)) + " & blake2b:" + minifyHash(hex.EncodeToString(result512)) + " vs. given: " + hex.EncodeToString(digest))
 			} else if StrongDigest {
-				return []byte{}, fi.Size(), errors.New("Invalid digests: SHA-1 checksums are no more accepted. Calculated sha1:" + hex.EncodeToString(result160) + " & blake2b:" + hex.EncodeToString(result512) + " vs. given: " + hex.EncodeToString(digest))
+				return []byte{}, fi.Size(), errors.New("Invalid digests: SHA-1 checksums are no more accepted. Calculated sha1:" + minifyHash(hex.EncodeToString(result160)) + " & blake2b:" + minifyHash(hex.EncodeToString(result512)) + " vs. given: " + hex.EncodeToString(digest))
 			}
 
 			for k := range result160 {
 				if result160[k] != digest[k] {
-					return []byte{}, fi.Size(), errors.New("Digests doesn't match: calculated: sha1:" + hex.EncodeToString(result160) + " & blake2b:" + hex.EncodeToString(result512) + " vs. given: " + hex.EncodeToString(digest))
+					return []byte{}, fi.Size(), errors.New("Digests doesn't match: calculated: sha1:" + minifyHash(hex.EncodeToString(result160)) + " & blake2b:" + minifyHash(hex.EncodeToString(result512)) + " vs. given: " + hex.EncodeToString(digest))
 				}
 			}
 		} else {
 			for k := range result512 {
 				if result512[k] != digest[k] {
-					return []byte{}, fi.Size(), errors.New("Digests doesn't match: calculated: " + hex.EncodeToString(result512) + " vs. given: " + hex.EncodeToString(digest))
+					return []byte{}, fi.Size(), errors.New("Digests doesn't match: calculated: " + minifyHash(hex.EncodeToString(result512)) + " vs. given: " + hex.EncodeToString(digest))
 				}
 			}
 		}