17:
25:
162:
16:
73:. In 1955, NSA produced some 1,660,000 rolls of one time tape. The logistical problems involved in the generation, supply and destruction of sufficient quantities of key tape limited its use to only the most sensitive traffic. In the 1950s. the U.S.
66:, of sensitive information leaking by way of unintended electromagnetic radiation for the circuits used inside encryption machine was first discovered coming from the 131B2 mixers used in SIGTOT.
43:
communication that was used by the United States during World War II and after for the most sensitive message traffic. It was developed after security flaws were discovered in an earlier
135:, National Security Agency (NSA), Volumes I, 1973, Volumes II 1981, partially released 2008, additional portions declassified October 14, 2015
199:
218:
145:
228:
223:
192:
78:
55:
and used the same Bell
Telephone 132B2 mixer as SIGCUM. The British developed a similar machine called the
132:
70:
185:
74:
24:
63:
69:
SIGTOT required large amounts of key tape to operate on a continual basis, which was needed for
169:
144:
Melville Klein, "Securing Record
Communications: The TSEC/KW-26", 2003, NSA brochure, p. 4,
102:
28:
Bell
Telephone 131B2 mixer used to combine (xor) one time-tape with teleprinter signals
212:
44:
36:
40:
77:
began developing a replacement, an effort later taken over by the newly formed
52:
161:
118:
103:"Teletypewriter Set 131B2, War Department Technical Manual TM-11-2209"
133:
A History of U.S. Communications
Security; the David G. Boak Lectures
48:
20:
Special paper tape reader (transmitter distributor) used with SIGTOT
82:
56:
23:
15:
59:. Later an improved mixer, the SSM-33, replaced the 131B2.
173:
128:
126:
193:
8:
200:
186:
168:This cryptography-related article is a
94:
81:and resulting in the fielding of the
7:
158:
156:
172:. You can help Knowledge (XXG) by
14:
160:
1:
47:for the same purpose, called
119:SSM-33 (SIGTOT) Cryptosystem
245:
155:
62:The phenomenon, codenamed
51:. SIGTOT was designed by
79:National Security Agency
219:History of cryptography
39:machine for encrypting
29:
21:
71:traffic flow security
27:
19:
75:Army Security Agency
229:Cryptography stubs
224:Encryption devices
85:(ROMULUS) system.
30:
22:
181:
180:
236:
202:
195:
188:
164:
157:
147:
142:
136:
130:
121:
116:
110:
109:
108:. February 1946.
107:
99:
244:
243:
239:
238:
237:
235:
234:
233:
209:
208:
207:
206:
153:
151:
150:
143:
139:
131:
124:
117:
113:
105:
101:
100:
96:
91:
12:
11:
5:
242:
240:
232:
231:
226:
221:
211:
210:
205:
204:
197:
190:
182:
179:
178:
165:
149:
148:
137:
122:
111:
93:
92:
90:
87:
13:
10:
9:
6:
4:
3:
2:
241:
230:
227:
225:
222:
220:
217:
216:
214:
203:
198:
196:
191:
189:
184:
183:
177:
175:
171:
166:
163:
159:
154:
146:
141:
138:
134:
129:
127:
123:
120:
115:
112:
104:
98:
95:
88:
86:
84:
80:
76:
72:
67:
65:
60:
58:
54:
50:
46:
45:rotor machine
42:
38:
37:one-time tape
34:
26:
18:
174:expanding it
167:
152:
140:
114:
97:
68:
61:
32:
31:
41:teleprinter
213:Categories
89:References
53:Leo Rosen
64:TEMPEST
49:SIGCUM
35:was a
33:SIGTOT
106:(PDF)
83:KW-26
57:5-UCO
170:stub
215::
125:^
201:e
194:t
187:v
176:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
