i'm trying to pass some JSON data encrypted to my app but seem when i decrypt it my script add some 00 to hexe code making it impossible to be serialized i've tried to pass data uncrypted and crypted and the only difference i found is 00 at the end that is how i read JSON if isn't Encrypted NSLog(@"A) %@", response ); NSMutableArray *json = [NSJSONSerialization JSONObjectWithData:response options:kNilOptions error:&error]; NSLog(@"B) %@", error); that is NSLog Output 2012-03-28 00:43:58.399 VGCollect[5583:f803] A) <5b7b2274 69746c65 223a2252 696c6173 63696174 61206c61 20707269 6d612045 7370616e 73696f6e 65206469 20526167 6e61726f 6b204f64 79737365 79222c22 63617465 676f7279 223a225b 20505356 69746120 5d222c22 696d6755 726c223a 22494d41 4745535c 2f323031 325c2f30 335c2f30 30303038 3536345f 31353078 38302e6a 7067227d 2c7b2274 69746c65 223a2250 68616e74 61737920 53746172 204f6e6c 696e6520 3220616e 63686520 73752069 4f532065 20416e64 726f6964 20222c22 63617465 676f7279 223a225b 20495048 4f4e452c 2050432c 20505356 69746120 5d222c22 696d6755 726c223a 22494d41 4745535c 2f323031 325c2f30 335c2f30 30303038 3437355f 31353078 38302e6a 7067227d 2c7b2274 69746c65 223a2250 72696d69 20536372 65656e73 686f7420 696e2061 6c747261 20726973 6f6c757a 696f6e65 20706572 202e6861 636b5c2f 5c2f7665 72737573 222c2263 61746567 6f727922 3a225b20 50533320 5d222c22 696d6755 726c223a 22494d41 4745535c 2f323031 325c2f30 335c2f30 30303038 3437325f 31353078 38302e6a 7067227d 2c7b2274 69746c65 223a2269 6c206e75 6f766f20 444c4320 64692046 696e616c 2046616e 74617379 20584949 492d3220 636f6e66 65726d61 746f2061 6e636865 20696e20 416d6572 69636122 2c226361 7465676f 7279223a 225b2050 53332c20 58333630 205d222c 22696d67 55726c22 3a22494d 41474553 5c2f3230 31325c2f 30335c2f 30303030 38343439 5f313530 7838302e 6a706722 7d2c7b22 7469746c 65223a22 52656769 73747261 746f2069 6c206d61 72636869 6f205461 6c657320 6f662058 696c6c69 6120696e 20457572 6f706122 2c226361 7465676f 7279223a 225b2050 5333205d 222c2269 6d675572 6c223a22 494d4147 45535c2f 32303132 5c2f3033 5c2f3030 30303834 34385f31 35307838 302e6a70 67227d2c 7b227469 746c6522 3a225376 656c6174 69202e68 61636b5c 2f5c2f56 65727375 732e2065 202e6861 636b5c2f 5c2f5365 6b616920 6e6f204d 756b6f75 206e6922 2c226361 7465676f 7279223a 225b2050 5333205d 222c2269 6d675572 6c223a22 494d4147 45535c2f 32303132 5c2f3033 5c2f3030 30303834 33345f31 35307838 302e6a70 67227d2c 7b227469 746c6522 3a22476f 6e205061 6b752050 616b7520 50616b75 2050616b 75204164 76656e74 75726520 756e206e 756f766f 2067696f 636f2064 69204e61 6d636f20 42616e64 6169222c 22636174 65676f72 79223a22 5b203344 53205d22 2c22696d 6755726c 223a2249 4d414745 535c2f32 3031325c 2f30335c 2f303030 30383432 385f3135 30783830 2e6a7067 227d2c7b 22746974 6c65223a 224e756f 76652069 6d6d6167 696e6920 6520696e 666f2064 69204669 72652045 6d626c65 6d204177 616b656e 696e6722 2c226361 7465676f 7279223a 225b2033 4453205d 222c2269 6d675572 6c223a22 494d4147 45535c2f 32303132 5c2f3033 5c2f3030 30303834 31365f31 35307838 302e6a70 67227d2c 7b227469 746c6522 3a225072 696d6520 696d6d61 67696e69 20646569 206e756f 76692044 4c432064 69204669 6e616c20 46616e74 61737920 58494949 2d32222c 22636174 65676f72 79223a22 5b205053 332c2058 33363020 5d222c22 696d6755 726c223a 22494d41 4745535c 2f323031 325c2f30 335c2f30 30303038 3431325f 31353078 38302e6a 7067227d 2c7b2274 69746c65 223a2249 6e206172 7269766f 20717565 73746f20 41757475 6e6e6f20 45706963 204d6963 6b657920 323a2054 68652050 6f776572 206f6620 54776f22 2c226361 7465676f 7279223a 225b2050 53332c20 5769692c 20583336 30205d22 2c22696d 6755726c 223a2249 4d414745 535c2f32 3031325c 2f30335c 2f303030 30383430 385f3135 30783830 2e6a7067 227d5d> 2012-03-28 00:43:58.410 VGCollect[5583:f803] B) (null) instead that is how i serialize my crypted JSON NSData *decryptBase64 = [GTMBase64 decodeData:response]; NSData *decrypt3DES = [Crypt TripleDES:decryptBase64 encryptOrDecrypt:kCCDecrypt key:@"2b9534b45611cbb2436e625d"]; NSLog(@"A) %@", decrypt3DES ); NSMutableArray *json = [NSJSONSerialization JSONObjectWithData:decrypt3DES options:kNilOptions error:&error]; NSLog(@"B) %@", error); and that is the NSLog output 2012-03-28 00:41:51.525 VGCollect[5529:f803] A) <5b7b2274 69746c65 223a2252 696c6173 63696174 61206c61 20707269 6d612045 7370616e 73696f6e 65206469 20526167 6e61726f 6b204f64 79737365 79222c22 63617465 676f7279 223a225b 20505356 69746120 5d222c22 696d6755 726c223a 22494d41 4745535c 2f323031 325c2f30 335c2f30 30303038 3536345f 31353078 38302e6a 7067227d 2c7b2274 69746c65 223a2250 68616e74 61737920 53746172 204f6e6c 696e6520 3220616e 63686520 73752069 4f532065 20416e64 726f6964 20222c22 63617465 676f7279 223a225b 20495048 4f4e452c 2050432c 20505356 69746120 5d222c22 696d6755 726c223a 22494d41 4745535c 2f323031 325c2f30 335c2f30 30303038 3437355f 31353078 38302e6a 7067227d 2c7b2274 69746c65 223a2250 72696d69 20536372 65656e73 686f7420 696e2061 6c747261 20726973 6f6c757a 696f6e65 20706572 202e6861 636b5c2f 5c2f7665 72737573 222c2263 61746567 6f727922 3a225b20 50533320 5d222c22 696d6755 726c223a 22494d41 4745535c 2f323031 325c2f30 335c2f30 30303038 3437325f 31353078 38302e6a 7067227d 2c7b2274 69746c65 223a2269 6c206e75 6f766f20 444c4320 64692046 696e616c 2046616e 74617379 20584949 492d3220 636f6e66 65726d61 746f2061 6e636865 20696e20 416d6572 69636122 2c226361 7465676f 7279223a 225b2050 53332c20 58333630 205d222c 22696d67 55726c22 3a22494d 41474553 5c2f3230 31325c2f 30335c2f 30303030 38343439 5f313530 7838302e 6a706722 7d2c7b22 7469746c 65223a22 52656769 73747261 746f2069 6c206d61 72636869 6f205461 6c657320 6f662058 696c6c69 6120696e 20457572 6f706122 2c226361 7465676f 7279223a 225b2050 5333205d 222c2269 6d675572 6c223a22 494d4147 45535c2f 32303132 5c2f3033 5c2f3030 30303834 34385f31 35307838 302e6a70 67227d2c 7b227469 746c6522 3a225376 656c6174 69202e68 61636b5c 2f5c2f56 65727375 732e2065 202e6861 636b5c2f 5c2f5365 6b616920 6e6f204d 756b6f75 206e6922 2c226361 7465676f 7279223a 225b2050 5333205d 222c2269 6d675572 6c223a22 494d4147 45535c2f 32303132 5c2f3033 5c2f3030 30303834 33345f31 35307838 302e6a70 67227d2c 7b227469 746c6522 3a22476f 6e205061 6b752050 616b7520 50616b75 2050616b 75204164 76656e74 75726520 756e206e 756f766f 2067696f 636f2064 69204e61 6d636f20 42616e64 6169222c 22636174 65676f72 79223a22 5b203344 53205d22 2c22696d 6755726c 223a2249 4d414745 535c2f32 3031325c 2f30335c 2f303030 30383432 385f3135 30783830 2e6a7067 227d2c7b 22746974 6c65223a 224e756f 76652069 6d6d6167 696e6920 6520696e 666f2064 69204669 72652045 6d626c65 6d204177 616b656e 696e6722 2c226361 7465676f 7279223a 225b2033 4453205d 222c2269 6d675572 6c223a22 494d4147 45535c2f 32303132 5c2f3033 5c2f3030 30303834 31365f31 35307838 302e6a70 67227d2c 7b227469 746c6522 3a225072 696d6520 696d6d61 67696e69 20646569 206e756f 76692044 4c432064 69204669 6e616c20 46616e74 61737920 58494949 2d32222c 22636174 65676f72 79223a22 5b205053 332c2058 33363020 5d222c22 696d6755 726c223a 22494d41 4745535c 2f323031 325c2f30 335c2f30 30303038 3431325f 31353078 38302e6a 7067227d 2c7b2274 69746c65 223a2249 6e206172 7269766f 20717565 73746f20 41757475 6e6e6f20 45706963 204d6963 6b657920 323a2054 68652050 6f776572 206f6620 54776f22 2c226361 7465676f 7279223a 225b2050 53332c20 5769692c 20583336 30205d22 2c22696d 6755726c 223a2249 4d414745 535c2f32 3031325c 2f30335c 2f303030 30383430 385f3135 30783830 2e6a7067 227d5d00> 2012-03-28 00:41:51.530 VGCollect[5529:f803] B) Error Domain=NSCocoaErrorDomain Code=3840 "The operation couldn’t be completed. (Cocoa error 3840.)" (Garbage at end.) UserInfo=0x6ccdd40 {NSDebugDescription=Garbage at end.} as u can see the only difference between 2 NSlogs is 00 at the end of second hexcode and the error on serialization of it do u know how fix that ? idk if is needed, that is my script for encrypt data +(NSData*)TripleDES:(NSData*)plainData encryptOrDecrypt:(CCOperation)encryptOrDecrypt key:(NSString*)key { const void *vplainText; size_t plainTextBufferSize; plainTextBufferSize = [plainData length]; vplainText = (const void *)[plainData bytes]; CCCryptorStatus ccStatus; uint8_t *bufferPtr = NULL; size_t bufferPtrSize = 0; size_t movedBytes = 0; // uint8_t ivkCCBlockSize3DES; bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1); bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t)); memset((void *)bufferPtr, 0x0, bufferPtrSize); // memset((void *) iv, 0x0, (size_t) sizeof(iv)); // NSString *key = @"123456789012345678901234"; NSString *initVec = @"init Vec"; const void *vkey = (const void *) [key UTF8String]; const void *vinitVec = (const void *) [initVec UTF8String]; ccStatus = CCCrypt(encryptOrDecrypt, kCCAlgorithm3DES, (kCCOptionPKCS7Padding | kCCOptionECBMode) , vkey, //"123456789012345678901234", //key kCCKeySize3DES, vinitVec, //"init Vec", //iv, vplainText, //"Your Name", //plainText, plainTextBufferSize, (void *)bufferPtr, bufferPtrSize, &movedBytes); NSData *result = [NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)movedBytes]; return result; }